I downloaded and installed RC2 without trouble. Logos 4 worked fine.
I got a notice in the notifier area of 1.5 MB of resources being downloaded (I assume my two 12 Days of Christmas purchases). Then got a request to install them. Clicked on that. Logos 4 closed, then I got a Windows message stating that Logos 4 had not closed correctly. I let it send the log file to MS. Attached is the Logos log file.
Logos 4 successfully opened after that and it is currently indexing.
1781.Logos4logs.zip
