If a content type is added to a doc library and a file inside the library is changed to that content type, but its EditForm.aspx page doesn’t show all of the properties that belong to the content type (1 or more columns are missing from the edit page), the content type IN THAT LIBRARY may be corrupted.
IN THAT LIBRARY (not in the Content Types Gallery):
- disassociate the affected files from the struggling content type (don’t delete any existing metadata);
- delete the content type;
- re-add it to the library; and
- change the content type of the disassociated files.
The files should either appear where they’re supposed to in the library (if metadata exists) or will be available for complete property editing.
Does someone have a better solution?