F7 E1 identifies a speed-sensing problem on documented Whirlpool front-load models: the motor does not reach the speed required by the cycle.
If it was just installed or the load changes
The manufacturer documentation recommends checking the shipping materials and overloading. If the first wash fails, review the unpacking section of the manual and confirm that the installer removed the intended shipping locks. Do not run the machine to see what happens with them in place.
If the error started with an especially large load, stop the cycle, wait for the door to unlock, and reduce the laundry according to the program. A bulky item does not become acceptable just by selecting a higher speed.
What the code describes and what still needs diagnosis
F7 E1 describes a speed that the control cannot confirm. By itself, it does not prove that the motor, a sensor, or the electronics have failed. Note whether the drum tries to turn, whether the failure appears at startup or during spin, and whether it began after the appliance was moved.
Only perform the retry the panel calls for after correcting the accessible condition. If it returns, request service. The explanation of the speed sensor helps the technician understand what to check; it does not require measuring circuits or disassembling the motor.
Stop using it if the attempt to spin produces unusual knocking or the appliance moves.