help !!! bmw m3 smg stuck in neutral

[zebi]

hi
i have mt bmw m3 2002 smg was driving it then the gearbox light came on started flashing and put itself in netral and then when i swithced the engine off and tried starting again didnt wana start so i found a fuse blown changed the fuse then it started up fine that was all on monday then

tuesday was on way home and done same thing checked fuse was ok changed relay still nothing put my diagnostic machine on it just comes up with 4 undocumented codes can anyne help any ideas wat it is and how much it could cost me many thanks

[Sidewindow]

Try opening and closing the bonnet as the bonnet close sensor may be dirty? Hopefully something simple like that.