Hello everyone,
quite a few users on the discord (me included) found this issue after updating.
Link to the Discord-Thread:
https://discord.com/channels/542985647502393346/1186680273987965058
Whatever the bug is, it prevents DCS from spawning any Ground vehicles (Like MBT90s or LAVs) and apparently ships too.
I managed to stop this from occuring by disabling my mods, one after the other, and figured out that it must be the JAS39 Gripen mod in my case. However, other users reported the same issue with other mods, like the VSN F4 Mod. For me, It only occurred with the Gripen, but not with i.e. the VSN F35 or VSN YF12 Mods.
I linked the Discord forum thread.