I noticed an issue with the book panel.
For some reason sometimes it shows the icon for "file is open" on some files even though they're not opened in Indesign.

When I open and want to save them, Indesign want me to define a filelocation again. It seems that Indesign lost the connection to the original file then.

When saving the file (I usually overwrite the existing one) Indesign crashes.

See attached screenshot for the "opened file"-icon in the book panel.