Just to add a bit of clarification to PPQ's helpful post, note that you need switch the BETA "original_release....." version. It's not a about the patch but restoring the original game assets.
However, I think the issue is more along the line of what PPQ was saying about folders. You need to make sure you installed into the correct mods folder. The Steam version has an odd folder structure. You have two BTS folders. The lower level BTS folder has the Mod folder that you need to install the mod into.
Another, even better option, is to just install Bug into your Custom Assets folder. You don't have to load it.