I have also experienced the "Configuration file corrupted. Some of my saved configurations have been fine, others not. Not able to load it.", more than once now, with Multibeast 8.2.3 (1). Multibeast saves configuration files as binary plist files. It is possible to convert binary plist files to XML. Doing this should result in a human readable file. In my case, I was able to see the configuration options I saved in the file. I can't be 100% sure that nothing was lost given the file says it is corrupt, but it looks like everything is there. The plutil command line utility comes with OS X and can be used to do the conversion.
Make a copy of the file first, because plutil works on the file in place.
cp yourconfigfilename.mb yourconfigfilename.plist
plutil -convert binary1 yourconfigfilename.plist
grep -i '<string>Drivers' yourconfigfilename.plist
or if you want to see the entire file just open it in the text viewer/editor of your choice, e.g.
less yourconfigfilename.plist
Output of the grep command should be several lines similar to...
<string>Drivers > Audio > Realtek ALCxxx > ALC892</string>
I've attached a corrupt .mb file (it just happened again!) I'm definitely in the habit now of "printing" my settings to a PDF file.