We have a program using the Solidworks.Interop.swdocumentmgr dll that ran for years with no issues on SW 2018.

We upgraded to SW 2024 and now when the .net code below is run,  numExtRefs has a value of ZERO, and extRefs has a value of Nothing.

The only thing I have changed in the code is the SwDMDocument23 (it used to be SwDMDocument18 because of a different version)

Dim dmDoc As SwDMDocument23

dmDoc =