Can anyone help solve this problem, I am sure this problem has been covered before!

I am working in Revit 2016 Structures and the project has been running for about 6 months. Previously I have created section without any problems and they are shown on the relevant plans. However any new section I create do not show on all plans with the exception of one, and low and behold it is not a plan that I am using anywhere.

I have gone though 33 reasons as to why something wont show and still they refuse to be visible. When I place a new section marker I get a warning message that reads "None of the created elements are visible in Structural Plan: 21006 GROUND View. You may want to check the active view, its Parameters, and Visibility settings, as well as any Plan Regions and their settings".

What I have noticed is that if I change to the plan that will allow me to see and create new section and then go to the new section, then switch on "show crop region" and reduce the height of the section to show just the roof area, by switching back to the plan view the section has now disappeared. If I then go back to the section and change the crop view to now show nothing but the ground floor and foundations. Then go back the the plan view the section marker is still visible. This would indicate that it could be a workset problem. I have made sure that I am the only one working in a shared model and that I have ownership of all worksets and still I have the same problem. I have also noticed that in properties under phasing filter if the filter is set to show all and phasing set to existing then I can see all the new section markers, however I then can't see the existing section markers!

Does anyone have any ideas how I can get the existing and new section markers to appear in the same view

Many thanks in advance