Try to re-download GIMP because although the installer has the same name it may have a newly fixed version. Confusing I know. Second, don’t use 2.9.0_pre! It has the same name but was updated at least 5 times. What you want is the 2.9.0 under “stable”.
Also read this post and its parent thread. I know it takes a while to navigate these problems but I am (and we are) here to help as usual.
