I have been using Acrobat Reader for quite some time now and one of the features that I rely on is the ability to reopen all the tabs that were open in the previous session, since I usually have at least 20 to 30 tabs open. Occasionally when the program is starting, I get error messages that indicates there was a problem opening some of the files from the previous session, but there wasn't any details to further explain the error. I recently figured out what is happening. It looks like the Recent files as seen on the Home window only contains the last 100 recently opened documents. Any documents that are beyond that 100 are pushed off the bottom of the list. If any of the currently open tabs are older than the 100 documents in the Recent list their file pathname is lost and when the application is reopened, the program has no way of reopening those tabs because they were not in the Recent list when the application was last closed. It would be a good idea to retain those open tabs file pathnames separately from the Recent list, so this error would not occur.