I am getting this error message on a document that I'm trying to test run through a workflow i just created.

The workflow is pretty simple - routes to a folder. When the document has been marked processed, it retrieves all of the metadata, stamps the document and moves it along. It appears that when it gets to the stamp portion, it gets a warning. I get the above error AND that the entry is locked. Then I can't delete the entry either, without closing out of Laserfiche and jumping back in. I haven't had this problem before, I also haven't used stamps before, but apparently I'm doing something wrong. Any ideas about how to fix this?