Hmm, interesting problem.
So I updated BP yesterday and tried launching it a few minutes ago. Got an error message. Other mods work fine.
If I leave FSO settings on Mod Default, I get a "I couldn't find an executable. Aborted" error.
Now this is interesting... If I manually select my FSO build (3.8.0-3) I get this:
"Blue Planet Complete" (1.0.5) requires "FSO" which is missing! (>=3.8.1-20190829)
So I'm thinking I need to update FSO. No updates on Knossos...so I check here...and I don't see any release thread for 3.8.1...
So...what gives? And what can I do to fix this?
EDIT: I did verify file integrity and no problems were detected.