[Gimp-user] Gimp 2.10 - Color to Alpha is greyed out

[MCBastos <forums gimpusers com>]

What it says in the subject. I installed Gimp 2.10 (final release) on Window 10
x64 and I'm so far unable to use the "Color to Alpha" tool -- the option is
simply greyed out. And yes, the image IS in RGB mode. I tried several images, in
fact. Otherwise, it seems to work fine, and I do like a number of the changes.

I even uninstalled Gimp, rebooted, deleted all GIMP-related folders (in my user
profile and such) to guarantee a clean reinstall, and then reinstalled it. Same
thing. I checked it first thing after rebooting (so no settings had changed),
and it's still unavailable.

The funny thing is, I got the PortableApps version today and installed it in a
separate folder... and this one WORKS. So it doesn't appear to be any kind of
weird incompatibility with my video driver or something.

Well, at least having the PortableApps version as a fallback for whatever
features don't work in the main install means that I won't have to downgrade to
2.8.22... but it's still really annoying to have a feature refusing to work.

Any thoughts?

-- 
MCBastos (via www.gimpusers.com/forums)