I t was doing that to me until I saved it and then ran it, rather than ran from the download and also selected the Repair option.
Sorry, save it?
The tings i try:
Just download it, click play, then update new version. Fail
Download it, click repair. Fail
Download it, put it into mod folder, and try play, and repair. Fail.
The same thing again, but try to make a shutcut. Fail
I try to run it as admin also, but the same thing happens. Im not very happy, but also all new things have some fail you know, but i just like to play :-(