Update issue with Thunderbird on Net Share

Hi,

ever since TB 6 (also the new TB 7) the update process wont work with Portable Thunderbird on our network share. It looks like it goes through the total update process but in the end I get a message that something went wrong and I should make sure that I've not installed more than one TB.

After clicking the failure message away the "old" TB will start up.

When I do the same on on usb stick or hard drive it'll work fine.

Anyone an idea if there is something I can fix or if this is something that had to be fixed in the portable version?

Every idea welcome

Thanks