SRS light on?? Airbag problem???
Possibly, possibly something else.
Being this is a Mercedes a dealer might be the best place to solve this .
Yes, airbag problem. That IS what the SRS light indicates.
Do NOT throw parts at the car, trying to fix it without a proper diagnosis
At the very least, get the codes read out and post them here
It could be an airbag, tensioner, electrical connector, etc.
Guessing wrong will get expensive real fast