Hello M.G. and Fred,

If you redownload the entire Composer 2.1.2, then it shouldn't matter whether you install it "on top" of 2.1 or whether you first uninstall Composer 2.1 before you install 2.1.2. Try installing "on top", and if that doesn't work, then uninstall 2.1 and then install 2.1.2.

Sorry for this trouble. I suspect the problem is that I had accidentally or carelessly released more than one version of 2.1. I'll be more careful in the future to use the a 4th version digit, such as 2.1.0.1 if I need to do that sort of thing.

Cheers
-- Mark