We have a Visual Studio workflow for SharePoint 2013 running correctly several hundred times over the last few years. There are however a few workflow instances that do not continue when completing the related workflow task but are still marked as "running". We do not have access to the logs as the corresponding approval tasks were executed several months ago.
According to some blog entries this seems to happen from time to time (while most of the information is rather outdated), but until now we haven't found a convincing cause for it and the "solution" is usually to reinstall the workflow, the task list, etc.
In our case this is not an option as we're in a production environment and don't want to lose any data on document versions, approvers, etc. We would prefer to "resume" the flow from its current state if there is any way to do that.
When investigating this, we had a look at the involved database tables and stored procedures, especially the
AllUserData table with the task item information as well as the
Workflow table. There is an
InstanceData field with a varbinary value (0x1234234234...) that might contain more information about the state of the workflow instance but we were unable to decrypt it for now.
Anybody knows what could be the cause for this behaviour and how we can resume the workflow? Is there a way to decrypt the InstanceData field in order to debug the workflow?