Yurgon

The JTAC/FAC was pretty clear:
"Abort, Abort, Abort! You have no permission!"
You dropped the weapon without clearance from the FAC. That's like the worst sin of Close Air Support, and you'd be lucky not to be grounded after such an incident. In case of collateral damage or blue on blue, a court-martial would be a likely consequence, and given this gross disregard for proper procedure, there'd be little an attorney could do in your favor.
When you work with the DCS in-game JTAC, open the comms menu again and follow the flow. For the most part it'll be fairly self-explanatory: Check in, receive 9-line, receive remarks and restrictions, read back 9-line and restrictions, call IN, get clearance, drop. It could get more complicated when the JTAC does the lasing, or when a specific final attack heading was requested that you are required to adhere to. But for the most part, just go with the flow.
All that said, the DCS in-game JTAC is fairly limited. If you get the chance to learn about CAS and experience it with a human JTAC/FAC it'll be 500 % more immersive.

Already reported here for the A-10C module:
 

Yup, it's already there in the C-101 and needs to be mapped in order for one of the pilots to activate it. IIRC it's the pilot who's currently on the controls who can activate the combined controls mode.

There's no MPCD in the A-10C, the displays are called Multifunction Color Displays aka MFCD.
In the legacy A-10C there was a HOTAS command to swap the left and right displays, so if you fly the original A-10C it's Coolie Switch Down Short.
In the A-10C II module that same command does something else entirely (SOI to HMCS).
In both A-10C and A-10C II you can use the Display Program Page:
on either MFCD, hold any of the OSBs 12 through 15 for 1 second or more select the page you'd like to have quick access to from OSBs 7 through 9 or OSBs 16 through 20; this option will then be highlighted finally select OSB 12 through 15 as the target for the page you've just selected in the previous step repeat the process for both MFCDs until you've set up the displays to your liking The manual explains this in more detail in the chapter "Display Program (DP) Page".

Don't select weapon stations, select profiles.
What you've been doing there is to select individual weapon stations, which in turn sets up manual profiles (M/whatever). These become lost as soon as they're deselected.
Instead, use the profile page to set up actual weapon profiles, and then either activate these weapon profiles through the DSMS PROF page or select them with DMS Right Short/Left Short with HUD as SOI.

When we talk about the DCS AI JTAC, then yes.
When we talk about a human JTAC, it makes all the sense in the world to keep the previous target points or coordinates, as the JTAC and the flight can then very easily correlate threats:
"Hitman, Hawg 2, tally two T-72 tanks approaching TRP Coors from the west, ready to engage with Mavericks on your request!"
This assumes that target points are somehow named or at least enumerated; a quick and easy solution is to call them "target reference points" and either go TRP1, TRP2, TRP3 and so on, or give them ad hoc names, like TRP Coors, TRP Foster, TRP Budweiser or whatever both parties can easily use and recall.
I would make it a habit to always keep previous target points and learn how to deal with the clutter. It'll come in handy in certain missions and of course when working with actual humans in the MP environment.

Yup, I'm pretty sure I read on the forum before that this is the exact reason: To ensure proper minimum spacing/separation between bombs, stations 5 and 7 can not release in pairs (and 5+6 or 6+7 should not be loaded simultaneously anyway).
In DCS we can certainly do as we like.
IRL pilots wouldn't start to taxi while performing important steps on the avionics. I think that's a complete non-issue: while DSMS (or any of the other items) is being loaded (aka transferred from the data cartridge, that we don't yet have in DCS), pilots wouldn't do much else and most definitely wouldn't taxi. If you look at somewhat official checklists, these steps are pretty far apart, and after LOAD ALL pilots will of course confirm that everything was loaded okay and there are no errors.
Also, taxi-out is usually accompanied by a quick brake-check and a quick wiggle of the nose wheel to ensure all these are working fine. In my squad we once had a pilot bump into the tail of another aircraft during a bit of a hold-up on the taxiway because his rudder pedal toe brakes weren't working or there was a controller conflict or whatever. IRL it could be a hydraulic issue within the brakes, so always ensure critical systems are working before you need them.
Fiddling with the displays during taxi, that's a great way to damage millions of dollars worth of equipment and create a safety hazard.
Again, in DCS we can do whatever we like, but I find that many steps out of real life checklists actually translate well to DCS, though the reason for failure might be different (hydraulics leak vs. controller conflict, for instance).

Without watching the track: The single most common cause is when the weapon's INS goes out of whack. That can happen in as little as a few minutes of relatively straight and level flight. When it happens, you'll see the weapon status go from "RDY" to something like "ALN RDY".
To correct the situation, you have to either turn by 90+ degrees or wiggle the wings. In the DCS A-10C, players should always make it a habit to plan for a significant heading change shortly before dropping JDAMs and other IAMs (CBU-103 and CBU-105 come to mind) on preplanned targets.

The 2.9.0 OpenBeta changelog has this:
 
Can you (or someone else) check if the issue persists in the Sinai terrain on the mentioned parking slots?

Did you close the canopy? In that case set the Intercom selector to Intercom in order to be able to communicate with the ground crew, and ensure that the battery is on. Or simply open the canopy again. 🙂
Are you spawning on a friendly airport (blue coalition airport for a blue coalition aircraft)?

That refers to the boresighting procedure for the AGM-65, as described in the chapter:
Maverick Display Symbols -> Boresight Symbol to Maverick Line of Sight
In the A-10C manual currently shipped with the Stable version of DCS, you'll find that on page 354.

Sorry, no. Repair and/or completely renaming Saved Games\DCS or Saved Games\DCS.openbeta should remove all custom user-installed changes and should restore all defaults. 🤷‍♂️

The A-10C was succeeded by the A-10C II Tank Killer. It's a slightly more modern version with a few new systems. Almost everything you see in old videos and tutorials still applies, the aircraft are like 95% identical. And the remaining 5% make it much more combat effective. 😉
The A-10C II Tank Killer is totally worth it. As an added bonus, it includes the old A-10C module, so you can choose which one you want to fly on a per-mission basis; old content that was designed for the A-10C is still going to remain compatible this way.
The A-10A is part of the Flaming Cliffs package. It's got simplified systems, it doesn't have a targeting pod and it's just all around outdated. Unless you intend to fly 1980s to 1990s type conflicts, I'd say there's little value in the A-10A for DCS World. Plus there's very little content for it, whereas the A-10C and A-10C II Tank Killer modules both have a plethora of missions, campaigns and tutorials available for them.
Can't go wrong with the A-10C II Tank Killer module! 👍

Besides running a repair (with slow and check-all-files options checked), you can try renaming your Saved Games\DCS or Saved Games\DCS.Openbeta folder.
That will remove all of your custom config, but will also remove just about everything that could have led to your DCS being broken. DCS will create a new folder with the bare minimum files in it.
If that fixes the problem, you could try to rename back your original one and figure out which files and/or mods cause the problem.
If a repair doesn't fix a problem, uninstalling and reinstalling usually won't, either.

To elaborate a little further, the AAP STEER PT dial selects the type of points that you can cycle between FLT PLAN (points in your currently selected flight plan), MARK (all mark points) and MISSION (all waypoints, initial points and airports stored in the aircraft's database, regardless if they're part of the flight plan or not).
This dial can only be set by the pilot, but when you create a markpoint, it's as if the jet conveniently set it to the MARK position for you in the background. In order to get back to flight plan points or mission points, cycle the dial to any position and set it back to the position you want.
What Stuka describes with FUNC + 9 on the UFC is just another way to switch between these 3 databases:
UFC FUNC + UFC 7: Flight Plan database UFC FUNC + UFC 8: Markpoint database UFC FUNC + UFC 9: Mission point database So that's just another way to achieve the same objective, and again this does not change the position of the AAP STEER PT dial down below the CDU, but it's exactly the same as if you rotated that dial.
That's good thinking. 🙂
If you happen to create a markpoint and then you want to get back to your new waypoint, just cycle the AAP STEER PT dial back to MISSION, or set UFC FUNC + UFC 9, then get back to the waypoint page with UFC FUNC + UFC 3 and in the CDU select WAYPOINT at LSK R1, and you should be right back at your previously created new mission point.
This probably sounds ridiculously complicated, but with a bit of practice, it's actually a pretty fast process.
Plus, if you create a markpoint in the meantime, there's probably a very good reason to do so and you'll probably want to focus your attention on that markpoint, so the jet switching to the markpoint database in this scenario actually makes sense IMO. 😉
Edit:
Oh I skipped this part. That's also good advice! In the WP page in the CDU, you can always call up the waypoint you're interested in, even if the jet has set the MARK or FLT PLAN database. Like Stuka says, just type the waypoint number or name and hit the appropriate data entry field in the CDU.

Can't say I'm aware of any nosewheel steering differences between Stable and OB (OpenBeta) as far as the A-10C and A-10C II modules are concerned.
Yes, that's one of the changes in the OB.
That's highly subjective, and is also a matter of when one answers this question (and when one reads the answer).
The A-10C II is going to get the front ARC-186 replaced by an ARC-210. That's going to be my number one most important change when it drops in OB.
It's important to understand that OB is just ahead of Stable by a few weeks. Eventually, everything we have in OB is going to get pushed into Stable. So whatever your personal top three OB features are right now, they're going to be part of Stable in a few weeks. And then OB is going to receive another set of new features, which will eventually get pushed to Stable, and the cycle keeps repeating over and over.
If you were using VR, there'd be no need for TrackIR. 😉
But if you don't use VR, then yeah, TrackIR is the way to go (there are certainly alternatives, but I've had TrackIR for many years and wouldn't miss it).
No idea about that eBay offer; I've got mine from the European TrackIR reseller, but not sure if that one's still in business. Looks like worldwide sales are handled by trackir.com, so you should be safe there. If you opt for a cheaper seller, it's up to you to assess their legitimacy.

Campaign updates come through the DCS Updater; that'll be part of a DCS update and you'll be offered to install it as soon as it becomes available. In case you run DCS through Steam, it'll even auto-update in the background as soon as Steam detects a new version.
But don't ask me how long it'll take to update The Enemy Within; I think BD is right on it, but it may still take a while. 😉

What exactly do you want to accomplish?
Do you want the TGP to follow what the Mav is seeing, or do you want the Mav to track what the TGP is seeing?
From your description, it sounds like you probably want the Mav to look at the exact same spot that the TGP is already looking at. Is that correct?
In that case, with the TGP looking at the target and the TGP already set as SOI, hit TMS Forward Long to set SOI as SPI, then make sure you've got Maverick selected in the other MFD, and finally hit the Slave all to SPI HOTAS command (China Hat Forward Long). The Maverick should now slave to whatever your TGP is looking at.
Always double check the lower left corner of the HUD for the current SPI Generator.

AFAIK the ARC-164 is an AM radio. In order to be able to listen to transmissions, they need to be amplitude modulated (AM).
Interestingly enough, UHF ADF works with both AM and FM signals.
Yeah, seeing the same, which is also exactly what was said in that 3 year old video.
Would be nice if they worked on the radios in general. 🙂
But AFAIK, the ARC-210 is going to replace the ARC-186 VHF AM (aka front) radio, and that's exactly the one that doesn't even have a homing indicator on the NMSP. 😉
According to the manual, that should not be necessary, but in DCS it is. Fascinating.
Edit: It's mostly correct in DCS. When TCN is selected in the NMSP and the TACAN Mode Dial is set to REC or T/R, and when UHF Homing is active, UHF Homing does indeed take precedence for Bearing Pointer 1. In my test, it's only when the TACAN Mode Dial is set to OFF that Bearing Pointer 1 incorrectly rests in the 3 o'clock position when it should instead point to the UHF homing source.
Awesome, thanks!
So, yeah, long story short: set the UHF transmission to AM instead of FM and then both listening to and homing in on it should work.

Just remember to always set the briefed frequencies; if I'm not mistaken, all radio transmissions do use the proper freqs, and not tuning some of them might make you miss out on a lot of information. 😄

Excellent report!
Every single step in the video looks fine, there should have been 6 out of 6 hits. The loadout as such is perfectly fine (we wouldn't likely see it in real life, but as far as I'm aware there's nothing there that would explain these GBUs missing their targets).
I also ran a quick test, recreating the conditions from your video as closely as I could, and in my attempt the first GBU-12 already killed the intended target.
I agree with Bignewy, a DCS repair would be the first thing to try.
If that doesn't work, I'd also try to rename the entire folder Saved Games\DCS (or Saved Games\DCS.openbeta) and try again; this folder holds your login data and all your input profiles and screen settings and so on. Just try to run a bare test like the one above with the minimum config required and see if the behavior changes. Maybe there's a mod, or a leftover from a mod, that somehow messes with the laser guided bombs? After testing, you can just remove the new folder Saved Games\DCS that was automatically created by DCS and rename your old one back to get all of your DCS config back, and depending on the outcome of the test you could then try to isolate the file or files that cause the problem (or if the problem still happens with the bare config, then you know that nothing in Saved Games\DCS had anything to do with it).
I also saw an F/A-18 track; maybe the proper A-10C track holds some clues, so if you can upload that, we can take a look at it and see if we spot anything.

That is true, and there were a few changes to the A-10C over the years, so some videos nowadays may be a bit outdated in some regards (regarding for instance the default positions of some switches in the cold cockpit, or TACAN and ILS stations being audible by default, which they no longer are, or the landing gear horn sounding with the Master Caution, which it no longer does). Plus of course the updates to the A-10C II module. However, the 2 modules are like 95% identical, and everything you learn about the old A-10C module also applies to the A-10C II module in DCS. The latter just has a few additional features.
On top of that, the in-game tutorials are sometimes not that accurate either, while at least some of the Youtubers go into incredible levels of detail in their explanations. The great thing about the in-game tutorials is the hands-on aspect, where you get to explore the cockpit and the systems in your own pace.
I'm not aware of any of them being available on Youtube, though maybe they already are.
And although I never actually did this myself, I do recommend to read the entire DCS A-10C manual - that is in depth, and you'll learn much more about the aircraft than you ever could through watching videos. There'll be tons of knowledge that comes in handy at a later time; it might not make a lot of sense initially, but eventually you'll remember reading about it. Personally, I've looked at individual chapters and use the manual as a reference all the time. Besides some of the better Youtube videos out there, the manual is one of the few places that properly explain the concepts that many newcomers get wrong, and that the in-game tutorials also fail to convey in any depth to speak of.
Speaking of good videos, the content of Gerry Abbott's videos (aka Fish) is top notch, and he really helped a lot of us guys out in the early days of the A-10C module. Coming back to these videos today, I sometimes think he should have avoided some unnecessary steps, but the DCS series still holds a wealth of knowledge where, even if something should be outdated by now, you'll still get the idea because he explains it very well.

I finally ran a quick test with an air-started A-10C II.
Initially, the bombs remained "RDY" for 12 minutes of flying straight and level, then they went "ALN RDY". After enough of a wing rock or enough of a heading change to get them back to RDY, this status only lasted somewhere between 30 and 90 seconds or thereabouts, then they went back to "ALN RDY".
However, after flying a 90° heading change and then back to my original heading (with roughly 60° Angle of Bank), they stayed RDY for another 7 or so minutes. So it would appear that they degrade a lot slower after strong heading changes and faster after small heading changes.
I can't tell whether or not that's realistic; going by what ASAP wrote, it seems this is not realistic.
However, I think it's been like this for a long time in DCS. Without somewhat compelling evidence that this is actually wrong, I don't think ED are going to invest resources in changing this behavior. So if anyone can generate a non-classified source (if in doubt regarding classification, you should definitely PM ED team members rather than posting something publicly, even if it's a link to a document that's already on the Internet), that would be fantastic.
In the meantime, it's always a good idea to plan for at least a 90° heading change shortly before reaching pre-planned targets that are to be served with IAMs (JDAM, WCMD), especially when the ingress is a long straight line. May not be realistic, but it's a valid workaround in DCS. 😉

Can you give an example that should definitely work, but doesn't?
In the A-10C at least, there were a couple of changes over the years which may not be reflected in the training missions and in older tutorials.
For instance, the Master Caution no longer sounds the "beep beep beep" alarm; this audible alarm is now reserved to low speed flying with the gear up.
TACAN doesn't just need to be tuned to a TACAN station, now you also need to lift the TACAN knob on the comms panel on the left side of the cockpit. This button now defaults to the off position and a TACAN station's morse code identifier can't be heard by default.
So it's possible there is an audio problem with your installation, or maybe you're just following outdated tutorials.
Since you talked about mods, the things that players should always do first in case of problems (testing after each step if it solved the problem, by launching DCS, testing, and quitting DCS):
Remove all mods Run a DCS repair (Windows Start -> Eagle Dynamics -> Repair DCS World [OpenBeta]) Rename C:\Users\{Your Windows Username}\Saved Games\DCS [or DCS.openbeta] If all of that fails, please record a short track or a video and share that with us.
Edit: Haha, overlap. 😉
Okay, you removed mods and repaired DCS, that's great! Master Caution and TACAN really sounds (*) like you're just following outdated advice.
(*) no pun intended 😄

That's a clear-cut case of "it depends". 😄
Obviously, you first need to enable the aircraft's Situational Awareness Datalink (SADL), which is very inappropriately labeled "JTRS" on the AHCP.
Once the jet is up and running and the HMCS is on, that's it.
Now, it depends on a bunch of factors.
Many AI flights will show up without a problem, including A-10C and F/A-18C (not sure about the F-16C).
For player controlled aircraft in Multiplayer, only A-10C (no matter if legacy or A-10C II) will show up, but F/A-18C and F-16C won't.
AH-64D use their own kind of datalink and don't show up on the HMCS at all, regardless if they're player-controlled or AI (the AH-64E uses Link 16, but we don't have the Apache Guardian in DCS yet).
The problem here is that SADL (used in the A-10) is not compatible with Link 16 (used in Hornet and Viper, IIRC) and needs a gateway, like an AWACS, but DCS doesn't seem to make that distinction, so in some cases aircraft with an incompatible type of datalink still show up in our A-10, in other cases they don't, and I'm not aware of any workarounds. So it's a mix of an actual real world problem together with a DCS-related problem.