First close all Avanquest software and download the following patch from this link here.
Double-click on the patch to run it, then a message will appear in French stating that no errors are found, click on OK to close.
Then click using the right-hand-side mouse button on top of the WebEasy shortcut icon on the desktop and select the option Run as Administrator (if such an option is not present press Properties then select option Compatibility and tick box in the section Privilege Level, then save and close with OK). This should help the program to start normally.
Please submit a ticket stating the exact license number, if you keep experiencing difficulties running the software.