I have the original civ iv and both expansions. I'm not using civ iv complete which seems to be the case in all the other cases I found. I didn't install BUG as a mod but in \Eigene Dateien\My Games\Beyond the Sword Eigene Dateien being the German name for My Docs. I used the installer, not the zip file.

When I start a game a get a blank technology advisor screen. There is only an exit button, nothing else. When I exit, I get the normal starting message and that's it. I can open the options menu with ctrl+alt+o, I can exit the game via esc. But I don't get any kind of interface in the game. The technology adviser stays blank, too.

Anybody help?

search the forum

I did. Maybe I'm just too plain stupid, but what I found was a lot of help if you are using civ iv complete, which I don't, the tip to put something into the registry, which already seems to be there and the tip to not forget to load the mod, but I didn't install it as a mod...

Try moving the BUG Mod folder to Egene Dateien\My Games\

No change. The window of the technology adviser opens, with nothing in it and when I exit that, the normal game starts but without any interface.

I recently come to know that some mods (e.g. Age of Ice) need administrator privileges in order to run properly and display the interface. Are you logged-in as admin?

Yes, I am.

Did you update BTS to 3.13? Do you have any other mods installed in the CustomAssets folder (i.e. not as a mod)? If all that checks out, try reinstalling BUG. I believe you can use the uninstaller, but otherwise just delete the CustomAssets folder in "My Games\BtS".