The proxy does not have a parent; therefore, it cannot find its source.
Varies from High to Low.
An internal relation between objects called Proxies has been broken. The proxy does not have a parent; therefore, it cannot find its source.
Sometimes, an island of objects is not accessible. In that case, the error is harmless.
This error is an internal error and will be investigated by a development team.
Some equipment items might not be able to find their parts.
What You Should Do
The following procedure deletes such objects:
Open the model.
Run the Clean Database custom command, and select the objects in error.