Which are the files responsible for the menu on Gimp 2.6?

[rich2005]

I do not know how you are installing the packages from https://launchpad.net/~malcscott/+archiv.../+packages As previous post, I do know that adding the PPA to the sources and apt (or package manager) does not work. Download the packages then install using dpkg

Your post indicates xenial (ubuntu 16.04) ie. "...Downloads/gimp_2.6.12-1ubuntu1.3xenial1_amd64.deb..."

I hope you are using xenial and as a check I have the required packages zipped on my storage here: https://my.pcloud.com/publink/show?code=...4JPjSJOj6y  - 14 MB

You will probably have to undo whatever you have done and the install goes like this: https://youtu.be/xACKSrtQLAw duration 4' 20"