Hi Venomdrop.

If you do not see button of some add-ons, which should have button in the Firefox interface, please read here How to Customize Firefox controls, buttons and toolbars.

I try with customize method but not working. What i do: I open customize.From the left side i pick up extension (mega.nz) and put on right up side.I close customize clicking on green field (exit customize) .Ok. The mega.nz is here but when i close firefox and open, this mega.nz extension is missing. I try and with (google translator) extension and not working.When i close firefox and open again all extensions which before i customize is missing.I can't find solution.All day i look around the net for solution but i can't found solution for this problem. Others suggestions?