1. Does your MainScreenButtons folder look something like this:
2. Check if you are using a custom skin:
Opt. | Preferences | Display --> Custom Skins --> choose default.
3. If your Mainscreenbuttons folder appears to be incomplete, replace it with a factory folder. I will send it to you in a PM. Close Band-in-a-Box, replace the files, then re-open.
Keep a backup of the "bad" folder so that we could compare them later.
If the folder appears to be complete with all files present, perhaps system security software is playing a role, blocking access to some files.
4. Try returning factory settings. To do this, close Band-in-a-Box, find the Preferences folder and make a copy of it to have as a backup. Next, delete all the files inside the Preferences folder, and re-launch the program.
Let us know what you find.