unable to load any new families of any kind eg doors or windows not already loaded previously into the current project

[bruce.norton]

An error occurred in family "Double Hung" that cannot be automatically resolved.
Error Information:
"Last type in system family "Basic Wall" cannot be deleted."

[michael_coviello]

Hello @bruce.norton 

Thank you for posting,    Does this article help to solve the problem?

problem.https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Error-Message-at-l...

If it does not help, Can you post a journal file to this thread?