This.Every scene doesn't need to be action packed or filled with tension.
There are plenty of parts of a book that you can write when you're not feeling the muse.
Every great book has one great moment. Until you get to it, dig down into the inner workings of something mundane in your fantasy world. Explain it to yourself, and write as you go. Later, if it's superfluous, take it out. Keep it for reference; you might need to know how the plumbing in the palace works someday!
But get the words down. Every day. Even if they're crappy words. You can fix crappy writing. You can't fix a blank page . . . except by writing. So get to it.