PSSE 33.12 UDM DLL import into PSSE 34.7 ?

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I have a number of User Defined Models (UDM) DLLs which are for generators in my interconnection queue, and they are in PSSE 33.12. My latest generation queue is in PSSE 34.7, and it's required to model ALL previous interconnection customers, which submitted models in PSSE 33.12.

How do I get those PSSE 33.12 DLL files to be usable in PSSE 34.7?

It seems stupid to throw away all my generation models on each update of PSSE, especially when utilities are accepting User Defined Models from generators. Is Siemens working on a method to make this sustainable for their customers in the future, with some version-agnostic DLL?