RW suddenly won't open any file not on startup screen

Mac Pro OS 10.9.5 | 24 GB
RW 6.3.6 opens fine but can only open project files appearing on the start up screen –– and then only the first time. Attempts to open any other file using the “other” button crashes RW. Attempts to open files from the recent files menu command crashes RW. Drag & Drop crashes RW.

Do these symtoms ring a bell with anyone? I may need a fresh install or a cache/preference file trashed but am unsure what files would need to be erased.

Thoughts-Insights gratefully sought.

Also: Used Time machine to go back to RW 6.3.5 but experienced same problem. Since it opens and works along just fine with my current project file immediately following a fresh start and doesn’t bock at doing a save as, I think the file is itself ok but can’t access other project files to check that 100%.

The solution: Do not have library set to open as a window and positioned on a 2nd monitor

Replying to my own post. Got an idea from another thread that described an issue with some (but not all) common symptoms. As soon as I selected the sidebar or popover settings for the library the problem of RW crashing on opening project files completely disappeared.