Losing my toolbar settings

This is a really basic question, but I can't find the answer in the manual.

When loading DOpus it is no longer opening with my toolbars in place. I am now having to manually close ones I don't want and open my custom ones. After using DOpus for years with no problems like this, I have forgotten how to make my setup the default. Can you help me?

Settings > Toolbars > Set As Default Toolbar Set.

If you're using Layouts, Styles etc. then they can also trigger toolbar changes and may need editing, which can be done via Settings > Preferences / Layouts and Styles. (If you always want the same toolbars, there are options for both layouts and styles so they don't override them and will use the defaults instead. You don't need to re-save them all each time the defaults change.)