I am having a similar issue. I am very sketchup savvy but this is driving me crazy. I am dealing with a very complex model and have taken a single section cut. I hid the section plane to export a clear image as to not have the gray haze over everything. I saved the file with the section plane hidden. When I open it back up I am unable to unhide the section plane. I have tried everything tha I can think of to get it to show up so I can delete it, but I'm still stuck. Anybody have any suggestions?

Thanks