UCA Client not displaying contacts in list

[Rich14]

3300 Rel 4.1
Standalone UCA 4.0
UCA Client 4.0.26.0
Windows 7 PC

Issue
On one UCA client the contacts display (Personal, Favourites and Corporate) have stopped displaying the users in the window. At the top of each window it still displays the number of contacts in each folder.
The problem is on the PC as the UCA user works fine if it is run from another P.C.
I have tried an uninstall and install but no change.
Can anyone confirm where there are any other files that the uninstall is not removing or am I missing something on the users display options ?

 

[jpruder]

You may need to reinstall. I would try that but first rename the current users/(affecteduser)/AppData/Roaming/Mitel/UC/(affecteduser)@fqdn to something else

 

[Rich14]

Found the cause of the problem when the issue appeared on 2nd user's PC.
Microsoft .net had done an automated update overnight on the PC's involved. When the I.T. staff rolled the second one back the UCA worked without problems again.
Working version of .net was 4.6.1