>Was it a one-time error, or is it reproducible? Was the computer extremely low on available memory at the time?

All other robots process as expected. I also stopped that specific robot and restarted it. It ended up in the same situation. So, I stopped all robots and restarted them all. The situation remains on one specific robot.

The UCase() is only used at those locations:

                ' Get the number of images
                lnOccurence = oApp.Occurs(UCase(lcSearchFor), UCase(lcHtml))

                ' Clear the collection
                oLink.Clear()

                ' Get all the images into the collection
                For lnCounter2 = 1 To lnOccurence

                    ' Get the url of the image
                    lnLocation = oApp.At(UCase(lcSearchFor), UCase(lcHtml), lnCounter2)

It is one of them which is causing the memory issue. My best bet is that it is the first line. lcHtml comes from a MHTML conversion. I assume there is a connectivity issue which is returning a very weird string into lcHtml which would then cause such reaction.