This was resolved by the following actions;
deinstallation and a cleanup of the registry.
We found a Reg Key for the License in the wrong place. After the deinstallation, the old Quest Registry Keys was under HKLM\SOFTWARE\Wow6432Node\Quest Software were still in place
The new installation was referreing to the old the saved information.
A manual cleanup is required. With the new install completed MfNE is up and running.