Robot Configuration Check
Robot Configuration Check sets the current Robot configuration as the required Robot Configuration. Therefore, if the Robot Configuration is changed, for example when changing a gripper or adding another axis, Flows and Subflows will be prevented from running as a preventive measure against unintended collisions.
Where to set it
Open Flow Config from the action bar of the Flow Editor and stay on the first tab, Flow Configuration. The check is the switch at the bottom, Prevent the Flow from running if Robot Configuration changes:

Turning the switch on records the Robot's modules as they are right now. Turning it off clears that requirement, and Flows run whatever the Robot is built from.
The switch is reached through a Flow's configuration, but it is a Robot-level setting — it is not stored with the Flow you happen to have open. Once it is on, every Flow and Subflow on that Robot is blocked after a configuration change, and turning it off anywhere turns it off for all of them.
When it fires
If the Robot's configuration no longer matches what was recorded, a Robot Configuration has changed dialog appears and Flows will not run. Usefully, it names the difference — which modules were added to and which were removed from the saved configuration — so you can tell a deliberate rebuild from something that came loose.
It also lists what to do: restart the Robot, or switch the module back (with the Robot powered off), or contact support. Deactivating the check in Flow Config gets you moving again, at the cost of the protection.
Because the point is to catch a changed cell, turn it on once the cell is commissioned and the tooling is final. Enabling it mid-integration means re-confirming it every time you fit a different gripper.
Related
- Tools — a Tool change is a common reason the check trips, and the selected Tool's TCP and mass are exactly what a stale configuration gets wrong.