Update failed due to files in the ~tmp folder?

Occasionally, a warning may occur that a POS update has failed because there are still files in a ~tmp folder. This can have various reasons, but often it is related to a previous update that was not completely cleaned up. This can happen due to antivirus measures that temporarily prevented certain files from being deleted. 

To solve this problem, all files in C:\Program Files (x86)\NedFox\RetailVista POS\~tmp\ need to be deleted. These files have no value and are blocking the installation of the update. By deleting these files, the update can still be executed.