PROBLEM - A user is not able to connect to the HUD client but is still able to connect to their PBX phone, web browser, etc.
SOLUTION - You give their personal IP address a static DNS connection, with the primary DNS being 8.8.8.8 and the secondary DNS being 8.8.4.4
PROBLEM - A user's phone is showing as being disconnected in the HUD, but the users PBX phone shows as being connected on their end.
SOLUTION - Disable the users firewall and restart the PBX phone.
PROBLEM - A user ends a call but the HUD client shows that they are still on the line with that call.
SOLUTION - Have the user right click their name on the top left corner of their HUD application and then choose "end call" from the drop down menu.