It is common for new users of the FM-2022 to get S-E errors on the FM-206 . 

You can ensure the grip is being sensed by the base unit by looking at the display , If the grip is being detected you should see " P-REM" displayed on the screen 

Remember the FM-2022 can only be used on the FM-206 in channel / Port 2 

One thing to  always check before getting to deep into things is the tips themselves are properly seated . When the unit is brand  new the Black O-ring on the Tweezer tips Body  tends to be a bit stiff making it a little difficult for the Blades to be seated properly into the grip.

Ensure the blade is seated all the way into the grip with the black O ring Recessed into the grip , it should not protrude upward at all . 

This will get easier over time and the O ring will loose some of its fresh tension and make for much easier removal and re installation of tips . 

 The S-E error is going to most likely be secluded to the tip themselves due to the reason that the tips have an integrated sensor , the S-E being " SENSOR ERROR " . If the sensor is to go bad or the tip has intermittent connection you can see these errors occur . 

As stated above please give the tips a good firm push and ensure they are seated as far as possible into the grip ( O- ring seated in hand-piece)  .

If the error persists beyond this attempt please contact American Hakko to initiate the opening of a RMA / repair case for the evaluation of the tips and grip .