If spark has to receive a lot of conference rooms, it will freeze the gui till all rooms are received.
In our case we have about 52 rooms and spark freezes up to ten seconds.
SPARK-1541:
-Refresh and invoke are now timertasks
-Addingroom is now swing thread
-Changed the way spark waits for refreshed conference rooms
Waiting for conference rooms and adding them to the table is now threaded and should not freeze spark.
Should working proper now