The Relicta demo worked for me without issue but when I tried to install the release version (setup_relicta_1.02_(64bit)_(41842).exe, etc.) I got this error most of the way through:

Internal error: Expression error 'Runtime Error (at 500:57): Out of string range.'

Clicked ok and the next error (while in the background the installer claims Relicta was successfully installed) is:

Runtime Error (at 211:63): Out Of Stack Range.

Clicked ok and the next error is the same except (at 211:69). Clicked ok and the next error is Invalid Opcode. Clicked ok and the install successful screen is in focus with launch or exit options.

The game (regular, DX12, and launch from the installer) fails to start with:

Failed to open descriptor file ../../../PAway/PAway.uproject

There is actually no PAway/PAway.uproject file and running innoextract on the installer shows that there isn't such a file in the archive.

And I randomly figured out the answer, which is that I ran out of disk space. Freeing up a bit more before the installation let it work. It looks like it needs an additional <15GB for the install on top of the 25GB that the installer claims to need. I'm not sure about the exact size, but that is similar enough to the installer size that I wonder if it makes a copy of the installer files before installing but after the disk space check (maybe related to almost all of the installed size being one file that is partly contained in each of the .bin files). There is still no PAway.uproject file but I guess the installer didn't notice that a file got cut short and the Unreal Engine thought it needed that file to find an additional resource. Or something.

Hi folks

I've another solution for you:
as I wrote there (www.gog.com/forum/general/gog_offline_game_installers_issue_work_in_progress/) a reboot of your machine could help.

I've got the same error installing a GOG game afterwards I played a 3D-Game. After rebooting and installing the new GOG game first I've got no error and a properly working game.

CU

Try to install Observation with offline installer - error, reboot, try to install Kingdom Come Deliverance - same error.
Install Solasta - error did not show. Maybe you have another solution?

Might be a necropost but considering this is the first thing that pops up when searching the issue I'll add another potential solution. If you have your non-unicode language set to something weird like Japanese or russian you might also see the "out of string range" error. In that case setting your non-unicode language to English could help.

I appreciate your help. That was a no-go for me though.

None of the solutions I've read about on GOG has helped. I get this error on large games like Cyberpunk and Uncharted. All my drives have Terabytes of extra room, so the possibility of not having enough room for a copy while installing isn't the problem either.

I'm guessing it;s because of the way GOG packages the offline installers.. As they get more and more recent HUGE sized games, it looks like I won't be able to play. This may end my dozen years with GOG.