I think guys may suggest a proven utility. Meanwhile, check the digital signatures tab if they are ok.
Most probably the files are ok, but some AV prevents DCS from checking its signatures.
For current Openbeta, version 1.5.1.46722.87
valid size of bin/DCS.exe is 6353816 bytes
SHA-256 hash is "c68fcbfc11f08469e5fc4e33b46e01e08f6be5f295119ca86d782f17d67494d1"
Oops, sorry for that. We'll correct this in on of the updates.
In the meantime, yhe forward compatible fix is:
if not net then net = {} end
net.download_speed = 256*1024
net.upload_speed = 128*1024
The installers are available since the ETA. Sorry for the misleading warning. Fixed this.
http://www.digitalcombatsimulator.com/en/downloads/world/beta/