Paratext 8.0.100.62 does contain some changes to how windows open and it sounds like the new code is getting into a loop. This change was done to prevent a data loss problem where caused by how the contents of a Bible module was being saved in the wrong book.
I haven’t been able to reproduce this given your steps, so it must be specific to the other windows you have open.
Send me a copy of your C:\Users{userName}\AppData\Local\Paratext80\ParatextLog.log file (shut down Paratext first). It may have clues.
When Paratext does get hung, there is a tool called ParatextForceShutdown.exe in C:\Program Files (x86)\Paratext 8 that you can use to stop it - this will also create a file that will show what it was doing.
John+Wickberg
Paratext Support