I had a broken stock damper and when I replaced it with a new Super Damper the new unit slid on the shaft with hand pressure. I have been told that the damper can slip and cause error codes to pop up, so I would like to fix this. Has anyone pinned the damper to the crank or found another way to fix this problem without replacing the crank shaft?

What year is your mini. I know there can be a slight difference in crank size depending on the year.
Do not try to run car. You will damage crank Or worse damage you engine.

It was engineered that way and I have yet to hear of any crank pulley spinning on the crank itself, rather than coming apart from the damper. If it's torqued to spec, it shouldn't slip.

Putting a pin is possible, but it would require drilling the crank... I've seen it mostly done on V8 with big power.

I have it torqued to spec that is for sure. It was not easy since my MCS is an automatic. I don’t think it is slipping but the ways at WMW told me it could be the cause of an error code P1498 since I cannot find any other reason for the the code to come and go like it does

I said that before knowing you had an ATI damper so I don't think that is the issue with your car.
I've installed well over 100 of them and the only cars we ever added the key to was the race cars using aftermarket cranks. So your street car doesn't need it.

Need to do some more diag to find out what the fault cause is.

Thanks for the input