Weedeater Riding Mower Dies when Clutch Engaged

I have a Weedeater riding mower that suddenly died. It starts ok but when I put it in gear and start to release the clutch it suddenly goes dead. Also, when I start to engage the mower about half way it suddenly goes dead. I am thinking it is an electrical problem but what? There is nothing caught in the blade. It is a Briggs and Stratton 12 HP engine. Thanks for any help you can give.

Most likely cause is a bad seat switch or the wire plug is not pushed on far enough to disable the internal safety switch biult in to wiring harness that attaches to the seat switch.

When you go to engage the blade, do it slowly and make sure your in nuetral with the foot on the brake, also make sure the mower has been running for a couple of minutes too. This is a quirky machine. Good luck.