Modifying (add/delete/change) line pattern throws error, wants to delete light fixtures

[damon.sidel]

In my current project file, whenever I try to modify, add/delete/change, a line pattern, Revit takes forever then throws a bunch of errors that it wants to delete light fixtures. There are three types of fixtures, all are recessed/hosted in ceilings.

I can create a new line pattern in another project file and copy/paste it into my project. It brings in the new line pattern and line style.

Thoughts?