Extrude Error

Hello the all knowing onshape forums.. I've been trying everything I know and I still encounter this error, even after pouring through many past forums. I have this sketch of a partial Welsh dragon which is going to be included in my project, however when I attempt to extrude it, it states 'Extrude 1 did not regenerate…

Hi there, I am modeling a part around the centerpoint of a circle, and it has been quite painful. I have 'posts' drawn up that need to be the same thickness as the outer ring, but when I try to extrude the sketch I get an error that it did not regenerate properly. The shapes don't seem to be closed now, but when I drew the…