Full-text: lots of FT_MASTER_MERGE waits in SUSPENDED state after multiple full-text indexes created (server hangs)
You will need to stagger the operations instead of doing all at once.  Connect item does not talk about accepting new connections.  But due to this wait threads are not being released (in your case) and new connectoins are not possible.

Ref:


https://connect.microsoft.com/SQLServer/feedback/details/1069538/fulltextindex-master-merge-operation-was-not-done
https://www.sqlskills.com/help/waits/ft_master_merge/


This is a known issue with SQL Server. From the connect item:


  This is caused by the way our current job scheduler is setup resulting
  in multiple master merge operations getting queued up but never
  signalled. To be clear, this only happens when multiple
  indexing/reorganize operations are invoked simultaneously - the
  indexing operation completes just fine and the results are queryable.
  It's only the master merge that times out and is re-scheduled for a
  later period of time.
  
  Due to the complexity of the fix we have decided to wait till the next
  major release before triaging it. At the moment, it is advised to
  stagger index populations in order to not cause such timeout issues.
  Please let me know if you have any further questions.