Re: how to resolve message "sim disabled" in lumia 730
A little bit more details would help to give a better answer but there are several possibilities.
1 You "blew up" the SIM by entering a wrong password to many times.
2 Your carrier has disabled it remotely for not paying a bill.
3 Someone ended the setvice, it was reported lost/stolen.
4 etc.
Your best bet is to take it in to your carrier and they can test it out.
If you need more assistance please register and reply on this post with some more details.