in VBA my code works fine. I can read the custom properties from SolidWorks file. In c# i get the error swDmDocumentOpenErrorFutureVersion.
I installed DM API from 2018, my key is from 2018 (same key used in vba), c# is debugged for "Any CPU" and 32 bit is enabled.
My File is from 2015 and the latest supported version from DM results 2018.
Where is the problem?