MOSS 2007 Workflow: An error has occured in Approval
If you create a custom approval workflow in a document library and select this option on the customize workflow screen:
[x] Update the approval status (use this workflow to control content approval)
SharePoint maybe report the following error:
“An error has occured in Approval.”
The solution for this problem is very simple, if you want your workflow to update approval status you need to enable content approval in your document library. To enable content approval here is what you need to do:
Go to your document library Settings > Versioning Settings and select ,Yes” for: “Require content approval for submitted items?” option.