The same thing happens for me, too. Deleting the application preferences in my user folder on a Mac fixed the problem temporarily.
I am experiencing the same problem.
This is a bug caused by Adobe waiting to load a disconnected server where one of your 10 recent files is located.
The workaround is to set the number of recent files to 0.
There is a long thread about it here: Indesign CC 2015 hangs everytime I access the file menu
I had the same issue, I found that changing the recent files to 0 worked. Bit of a workaround but fixed the issue. Thanks everyone who's posted for the help!