A few things could be generating that apparently. I've read about anti-virus software causing that error in many UE4 games, permissions can also hold it up so try running as an admit and whitelisting it on any anti-virus software you have.
UE4 also requires DirectX11 or 12 in some cases, so make sure that's installed and up to date as well.
Let me know if you still can't get it working after trying those things
Uninstalled 3rd party antivirus, and re-downloaded - No joy.
Checked dxdiag, DirectX12 is installed and up to date.
Confirmed that version 2.5 still launches as intended.
Reisntalled 3rd party anti-virus (Immunet - ClamAV based)
Confirmed version 2.5 still launches as intended.
I suspect an issue with the release that is available for download here.
Edit: Also tried running as admin in both states
Edit again: Also checked file properties, it is not blocked.
Oh wait you're right.
I was testing the files I was zipping and they worked fine, but after testing the old zip I uploaded I got the same error.
So I've rezipped the files, I've tested that zip version and it seems to be working fine so I've uploaded it. Please redownload the game and try again, sorry about that.
