Libgit2 error when loading project

Trying to load an ACA project that I've been working on for almost a year. When launching program, it opened a new project rather than the one I had been working on. Fine. When I tried to open the last project within the program it would either fail to launch and hang, or I would get the following error message (I could see the project behind it, including the last scene, etc.):

libgit2 error -1(2/failed to read descriptor: Input/output error) returned from git_commit_parent(&prevP, commitP.get(),0)

Mac0SX 10.11.6 , ACA Beta 6

?

Did just manage to load an older version, finally, after uninstalling/reinstalling