Transmission Fault

[MariowiththeM]

Hi Guys
sorry for my english, its not the best but i hope u understand it and can help me and give me some tips.

My M5F10 is tuned up to 799hp and 1060nm, but i never use the power. 2 Month ago i installed a new Upgrade SSP Clutch. it works and fits well and it feels by shifting up the gears very well. Last weekend i was driving by around 30km/h and put the throttle ca 15-20% to accelerate up to 60km/h. The Car starts shaking a little and shift crazy around and the failure "transmission error " appears. i turned the engine off and on and the error was dissapeared. After a few hundret meters it starts again and he shakin, shiftin random down or up. I shiftet with the pedals manual and he shows he is in 6. gear but i was drivin maybe 10km/h. Now i cant drive anymore and i have no idea whats broken. i take the DCT this week off the car and look. U Guys have any ideas? Mechatronik? Dualflywheel? Clutches? or the Transmission itlself?
Thank you 4 ur minds.