In Beta b10, I think I found a mistake in a Library procedure, and I changed the code slightly, which I think corrects the error. I got Error messages said that "targetDatabasePath does not exist. The database and procedure were _DatabaseLib and INITIALIZEDATABASE.
I added a let statement at the start of line 33 of that procedure, so now it reads
let targetDatabasePath = sandwich("",catcherror("",dbinfo("folder",targetDatabase)),info("databasefilename"))
That fixed the error. I have a second issue but will do a second post for that.