So, just to be clear, only one project (sequence) is greyed out? You have other versions of this sequence that are blue and playing normally?
That is correct.
Is everything greyed out? Video and audio or just audio? It’s a little hard to tell from the screen shot. Also, I see a little blue in your screen shot. Are there a few clips that are visible?
Good eyes! Everything is greyed out that has audio. The little bit of blue is/are clips with no audio