TL;DL: remove dataflow entities from downstream dataflows before deleting upstream dataflows.
I have a dataflow with Linked Entities to a few other dataflows--so a downstream dataflow with several upstream dataflows.
I wanted to "swap out" a few of these entities for newer versions, so I deleted the old upstream dataflows--with the intent of editing my downstream dataflow to replace the upstream GUIDs with the new ones--however upon deleting the upstream dataflows, the downstream dataflow became uneditable.
I submitted a support ticket and they said since the upstream dataflows can no longer be found, the downstream dataflow cannot be edited. My only option is to delete the dataflow and re-create--which will break the dataflows my users have built from this dataflow. What a mess.
So, always remove entities from dataflows before deleting the dataflows they reside in--or just don't delete them at all, just rename them.
