I had an error show up while editing the documentation in an offline DMD project. I had a single temporary location (V100) that had been automatically been added to the documentation database. I had then used the Replace function in the Ladder view to replace it with the permanent variable that I wanted to use. I had then right-clicked V100 in the documentation editor, and then clicked Clean Documentation Database. In the popup, I clicked the Refresh References. I then got a modal popup with a title of: "DmDesigner", and the text: "Encountered an improper argument". If I click either the OK button or the X I just get a ding, and it comes back. I cannot dismiss without forcing DMD to shutdown.