InDesign 2015 freezes if an unavailable server-side document is listed in File -> Open Recent...
This is with no open documents, no plugins, no modifications to panels, no involved preference changes, nothing.
Mouse over the File menu and it will lock the app up hard. Open -all- of the correct network shares holding -all- of the recent documents, and it works perfectly fine.
This is a maddening new behavior in InDesign 2015. InDesign CC -> Preferences -> File Handling -> Number of recent items to display = 0 feels like a dumb fix to a problem that never existed before. How does one get the attention of the product manager?
Same problem on ID CC 2015. Your workaround worked for me as well. I hope this can be resolved quickly as I make use of the recent files menu daily.
It is fixed in the latest patch! Huzzah!