You dont edit the Master Style. Editing rpg templates in the MS would cause the Revert system (that you can use to undo all edits to a template) to malfunction, plus it will disrupt vB upgrades.
You have to customise all templates on a per-style basis, unless you got Parent styles setup.
And yes, the backend should be working, however if something goes wrong on forumhome, please try searching around in this forum for similar occurrences, and if they are not covered, ask