Since we use that to detect when the mesh is already uploaded, and thus can be reprinted, this could cause problems, since, while we do properly set it to None when an error is returned, if the request never returns to us, or if a reprint is started while the mesh is still uploading, the print-job cache could be set while the mesh wasn't actually there yet. Which could in theory have maybe caused the problems we see.
CURA-8004