Just last week I had 2 problems occur that took this one solution to fix.
Initially any Task Pad with pictures as buttons was taking a very long time to load, sometimes over a minute. Assuming this was a HDD failure incoming, I imaged the drive and swapped it, the problem continued.
The day after the HDD swap, the POS stopped opening all together showing a Server Failure 139 message. Tried repairing the POS program, tried uninstalling and reinstalling, nothing was working.
Found this thread and decided it wouldn't hurt to try pulling some of the Temp files out and putting them in another folder, incase moving them made it worse. Took any Temp file from last week and moved it to another folder and the POS started connecting again, but still had trouble loading the Taks Pads with pictures.
Moved any Temp file that was from the past few weeks, when the issue seemed to start, and like magic the Task Pads started loading instantly again!
TL;DR ... if you are getting a Server Failure 139 or your Task Pads are very slow to load when they weren't before, try deleting your temp files back to about the time the problem started.