Description
Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 21.2, you may see that the Tile Interface Planner shuts down without saving your interface plan. This problem occurs when you make edits in the Tile Interface Planner and then run synthesis while the Tile Interface planner is still open.
Resolution
To avoid this problem, make sure you close the Tile Interface Planner before running synthesis.
This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 21.3.