Thx mattatobin, and Lootyhoof - it works!
I first tried resetting single maf leftovers from the edited MAFF add-on in about:config, - can be, I blew it even more with dozen times removing/re-installing wrong edited versions -, then went to mza extensions, comparing main and portable configs, but with no real clue what I'm doing
After a more experimental full reset in PM Troubleshooting I soon found myself twiddling with rather unknown things, so I choose to uninstall and remove everything old and shizzled. - My profiles reached back to FF stone age anyways and I already had considered starting from scratch before PM 26.
Fresh installation, add-ons and importing personal files took me not soo long and I have a clean brandnew Pale Moon 26 now. Everything's fine again.
- greets