SharePoint 2010 - Workflow randomly shows canceled

Question

When a item is approved from the manager task the workflow updates a entry in a calendar list with the status approved. This workflow fails sometimes with the following error.

The workflow could not update the item, possibly because one or more columns for the item require a different type of information. Access Denied

I have no idea why this happens. Here is my workflow code

Answer 1

Your images are not showing up so this is hard to diagnose, however it seems like you are trying to pass the wrong type of value to a variable, such as a string to a date/time.