Updating busy information greyed out
This display usually means the folder is not accessible at a low level, and this in turn is likely from either a fault in the filesystem entry for the file, or damage to your Mac’s hard drive formatting.
If we restore the database, we cannot copy the missing document because it would not have the correct App UNID. However, you really have to look at the two documents to make that decision.
Note that the Calendar Repair Tool does exactly that when trying to figure out which duplicate instance to keep and which one to discard.
Then after this a window with an update notification appears.
I chose there preferences, and I unmarked the checkboxes there.
After closing, the windows turned gray too for about 1 or 2 seconds, then the notification "no updates needed" appears.