MacOS X 10.12.5 doesn't recognize password

[cmdrdredd]

My father has an iMAC that he installed OS X 10.12.5 to and the log in won't recognize the password. Rolling back to 10.11.x and the same password works just fine. What happened? If we try to install 10.12.5 again will it do the same thing? I'm not really too savvy with OS X but I know the basics. What should we try here? I've never experienced something like this.

 

[Eug]

Should work fine. I made the upgrade with no problems. Weird. Any special characters, etc.?

Perhaps you should create a backup admin account just in case, and also remove the password for his account before the OS upgrade, and then add the password back in after the upgrade is complete. Maybe that will work.

 

[cmdrdredd]

There is one special character and a number. in 10.11 it works and after update it doesn't. It takes a whole heap of time to do a time machine restore from the NAS so it'll be annoying to have to keep doing this over and over lol. I was thinking of changing the password and trying that, or maybe I'll just start with what you mentioned. I'll have to see tomorrow since it's doing a restore and I wasn't going to sit around and wait for it. Probably won't finish up for hours.

 

[Eug]

Try making a new dummy/test account with a password containing that special character to prove if that's the culprit.