Can't get workflow subscription

I’ve installed the demo of Workflow Scheduler 2013 product and created my first task that invoked a simple 2013 workflow. This ran as expected until I made a modification to the workflow (removed a mail-sending step). After saving and re-publishing the workflow, the task ran but seemed to invoke the workflow in its original form (still sending email). This was unexpected behavior - it ignored my changes to the workflow somehow?

I’ve now deleted the original workflow, built a new one, and deleted and recreated my task in Workflow Scheduler. This new task fires off, puts the workflow in a running state, but the workflow never actually runs. Errors are being logged in the event viewer and ULS:

Category: Plumsail.WFScheduler

Can’t get workflow subscriptionThe given key was not present in the dictionary. at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at ›.š.‰‡(SPWeb )

Any help would be appreciated.

Thank you for letting us know about this, we will try to reproduce the issue and we will fix it in next release.