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Error: Changing a workflow and getting a state on a persisted Wor...

I was experimenting with Persistance and created some workflow instances and unloaded them. these appeared in my database with appropriate Guid's. I then closed the application and reopened it and returned the State of the workflow fine using:

Jeremy Thake

If you change the definition of a workflow and recompile it you need to change the assembly version. The existing instances (unloaded or in memory) need the original version of the type/assembly in order to be deserialized correctly. If you need to change the definition of an "in-flight" running instance you'll need to use the dynamic update functionality.

Thanks,
Joel West
MSFTE - SDE in WF runtime and hosting

This posting is provided "AS IS" with no warranties, and confers no rights

Joel West

That seems to imply more than just having to change the assembly version - the implication seems to be that we need to keep the old version of the workflow type around for as long as there are persisted instances of that workflow.

Does this mean that we'll end up with an application that references multiple different versions of our workflow type, each contained in it's own assembly?

piers7

Yes, you need to keep the original version that started the instance available. Binary serialization relies on being able to load the correct version of the assembly. If you change the workflow structure without versioning the assembly or you delete or remove the assembly deserialization will fail.

Thanks,
Joel West
MSFTE - SDE in WF runtime and hosting

This posting is provided "AS IS" with no warranties, and confers no rights

Joel West

reply 4

You can use google to search for other answers

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