I am using Pale Moon version 27.0.3 x64 on Linux Mint 18. I would like to have the forward and back stepper arrows on the scrollbar that does not change size. When I was using Firefox I was able to edit the Mint-X theme to enable the forward and backward stepper arrows and adjust the width of the scrollbar but Pale Moon is using a default theme which appears to be done inline. I have tried several themes by going through tools, and add-ons but I have not been able to find one with the arrows. I posted on the Pale Moon forums but have not had any suggestions.

I'm using Mint 17.3 KDE, and so far Pale Moon won't run. It installed, but won't run. So I can only take a stab in the dark here. But if FF extensions are compatible, have you tried Configuration Mania and GUI:config? Those allow a lot of extra changes that you'd have to about:config otherwise.
gentisle

Configuration Mania would not install in my version of Pale Moon. Gui:config installed but I could not find the configtool file to run it.

Yes, and I couldn't even get the Linux edition to work. But neither the Win32 or Win32 would load either of those extensions under Win 8.1 Pro. There's not a dark green plus in a circle anywhere on the browser? That's the GUI:Config menu. Or sometimes it shows up as "advanced settings" on the tools menu. Sorry, I couldn't be any help.

Now I get a message that GUI:config is not compatible with Pale Moon 27.0.3. Thank you for the suggestion.