How to fix Gear shift

@masabatamotete not enough detailed information here. We need to know what exact year and model your MB is. The C-class includes a few different mode. Next we need to know if your MB still starts and drives and if the transmission shifts etc. Usually the shaded block is the standard digital highlight which indicates what gear you have currently selected. If this block is stuck over "D" while your physical gear shifter is in Park (P), the vehicle's network is getting an incorrect gear signal. This triggers a no-crank/no-start condition because the car believes the transmission is in Drive.

That could be caused by a Electronic Selector Module (ESM) Failure. The W203 shifter module uses internal optical sensors to determine the lever's position. This may have failed. The ESM communicates with the Transmission Control Unit (TCU). A failed TCU will lose communication with the shifter, which can freeze the last known gear position on the cluster. I'd check on these two things first.