Two different projects with two different coworkers recently have had issues with feature lines defining the surface suddenly stop working as breaklines of the surface. Using the select within the site, will select the feature lines that work properly but will not select those that are misbehaving. Attempts to copy/move these feature lines to a new site will either fail or delete the feature lines in question.
Attempts to copy/move to the "None" site also results in failure.
The solution that seemed to work on both projects is to explode the feature lines back to polylines (explode once) and then create feature lines from objects to a new site and then add them back as breaklines within the new site.
However, the old site with no civil 3d objects remaining can not be deleted. The following error message occurs: "'SITE' could not be deleted. Perhaps it has children, or is referenced by another object."
Has anyone else recently have similar trouble or have a solution to deleting the corrupt site?
The projects are using Civil 3D 2021.2.
