Tried launching my 18' AMG GTS a few times, had a couple failed attempts, but on the last try, I hit the gas and for some reason the car suddenly shifted into Park.

Not sure why that happened, but this message popped up on the screen right after. " electronic rear axle differential lock inoperative" It disappeared after about five minutes once I turned the car off and back on.

It hasn’t come up again since, so I’m not sure if it’s something to be concerned about. Just wondering if anyone else has had a similar experience? What does this message mean?

A bit afraid to launch it again now as I might break something. If anyone has a good video showing the proper way that would be very appreciated.

 

Most of the time it's caused by a failing actuator in the electronic locking differential. When it happens the diff fails to lock properly. Especially during Race Start, the diff preemptively fully locks the rear differential for maximum traction off the line, so if you have a malfunction in the diff, then all bets are off. These suckers are expensive to replace, especially in the GT where the diff and transmission are one unit, so if the diff blows you are looking at a whole new transaxle. However, the actuator can be replaced w/o replacing the whole unit. Don't go to a dealership, though, they'll want to replace the whole shebang.