Can't edit Section Lines of Interior Elevations

[Christiaan]

Some of my Interior Elevation Viewports have morphed into some kind of Section Viewport, meaning I can no longer no long click on "Edit Sections Lines...", which is greyed out. 

 

Anybody know what's going on here and how I can bring back the previous functionality?

Edited February 5, 2021 by Christiaan

[Christiaan]

Seems to be something deeper going on. Tried to save and commit. VW hung and I had to force quit. When I reopened the Interior Elevations were back to normal; I could edit the section lines.

Edited April 29, 2021 by Christiaan