Hi Willem, I uninstalled the version selector, downloaded and installed an older model that reinstalled the version selector. After a reboot I could open the project from the explorer again.
I had the same issue, was thinking it was only me.
I deinstalled StudioPro & Version Selector , and reinstalled.
(In Windows App & features: Search for mendix, check for the new black&white Mendix app icons)
After that it worked again.