Can‘t Edit this nested family, WHY??

[1143413815422067]

Hi, you guys everyone!!
I just got a strange nested family, all in the attachment, surely this Nested Family is a Generic Family Type, but I can't edit it.
After I select it, there no "Edit Family" Button in the Ribbon, When I right-click it in the Project Browser, in the quick-menu, the "Edit" option is grayed out!!
So, what happened to this family?

[iamtintin]

It can happen with old revit families (which have been subsequently upgraded). See discussion below for more information.
https://forums.autodesk.com/t5/revit-architecture-forum/cannot-edit-family/td-p/2284480

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https://forums.autodesk.com/t5/revit-architecture-forum/cannot-edit-family/td-p/2284480