Often this happens when there is another version of the software confusing the authentication process. What the support team recommends in this situation is to uninstall the program and delete all the program files. Some of the program files are hidden. Specifically there is installation.ini files that will need to be deleted.

When searching Windows systems you will need to show hidden files or you will not find these files.

For further assistance in this manner you should also email support as they could help further.