The manifest file has only to do with the look of biab. If you delete it, you won't have gradient buttons but grey buttons.
"Read of address 00000000" means that the program tries to access to something that doesn't exists. Did you try to return to factory settings as suggested by Noel ?
I think that you can delete the file "intrface.bbw" too to remove your settings (maybe some members of this forum can confirm ?)


Free tools for Biab:
Biab Scales and BIArpeggio to practice scales/arpeggio
Biab Explorer: the other song picker