The system may need a reboot. Try this BMW approved procedure to reboot all electronic modules:
- disconnect the ground/earth/negative cable from the battery
- disconnect the positive cable from the battery
- short the 2 cables together for at least 10 minutes
- reconnect the positive cable to the battery
- reconnect the ground/earth/negative cable to the battery (sparking is ok)
- reset the clock
I've done this numerous times on my and friends! E46s. It will not damage anything.
If this doesn't work the disc reader may need to be cleaned. There are cleaning discs available on Amazon for under $10.