Cannot refresh or save dataflow - Cannot acquire lock for model

NAOS I'm experiencing something similar with one particular dataflow that has two entities connecting to an Azure SQL Database without using a gateway. It started failing on Thursday 02/01. The dataflow refresh status shows as "Failed" but the Entity refresh status for both entities shows as "Completed". There is no error message in the "Error" column. It fails on the scheduled refresh and a manual refresh.

When I try to modify the dataflow and save the changes I get the "cannot acquire lock for model" error message.

If I export the JSON and create a new replica dataflow in the same workspace by importing the JSON it works fine.

I will be interested to know if you find a solution!

NAOSRather than restart the whole capacity (which we would need to be done out of hours to minimise disruption) I went into Admin Portal >> Capacity Settings and under Workloads >> Dataflows increased the Max Memory by 1%, applied the change and then changed it back to its original setting and applied the change again. This only took a few seconds. The theory was that this would force the dataflow workload to restart which might clear the problem.

It appears to have worked as I am now able to refresh the dataflow ok, so this might be something worth suggesting to your IT Department as being less disruptive than restarting the whole capacity.