I have a couple of workflows made in SharePoint designer, that create a looping effect to process items in another list. Basically, one workflow starts when a yes/no field equals yes, the other starts when the same field equals no. They both have the same steps, getting information from the second list, and adding it to its own fields.
My problem is that occasionally, while these workflows are running, one of them will error. It has happened on both workflows at separate times. The error that is shown is "The workflow could not update the item, possibly because one or more columns for the item require a different type of information." with the outcome "Unknown Error".
I put some log steps into the workflow to try to figure out where the problem was, and it doesn't even get to the first log step, which is the first line of the workflow. It seems the workflow is failing at start, but not showing that on the workflow status.
And to confuse me even more, when I terminate the workflow and run it again, it runs fine, even though it is processing the same info.
Any ideas what could be causing this problem?