Pretty common. Though that looks like it's been welded / fixed before in some way and not very well. I had mine done and it didn't look anything like that.
Need a new bracket, new bolt, both available from BMW. Then just someone to weld it. Easy job for any garage that can weld though not sure if they can weld over that previous repair, not that I know anything about welding!
Cause is it's just not a great design, the new one is updated and beefier. I wouldn't go on any long drives if you can help it but the car's not going to disintegrate without it either. Cost all in probably £100-150 maybe. Think I paid around £100 a few years ago but obvs everything costs more these days.