MacOS Monterey installing problem ( checking null after download )

[thiasvm]

Hello guys. I hope you had a wonderful new years and I hope you can help me.

I got an older macbook pro 2017 from my mother the other day. It was installed with the Mac os Big Sur and it worked fine. Then i deleted her account so that i could make my own. After it was deleted and i installed my own account it rebooted ass the Mac os Mojave, which is working superb btw. But I want the Mac os Monterey because it is the newest version and the macbook also recommends it.

After downloading twice now I still cant instal it. It's getting stuck in that "Checking null" sequence and its so frustrating. I have searched the interwebs for a long time without finding a solution.
The Macbook is working as it should, did a diagnostic and there was no problem. There is also more than enough space for the update, so i really don't understand the problem... I hope you can help, usually some off you guys a truly Mac wizards ;-)

Best regards

thiasvm

 

[Mike Boreham]

In any change of ownership (even from my mother) situation I would do a complete erase and reinstall. New everything.

if you use the option+cmd+R method in This link it will install the latest OS compatible with the Mac, which should be Monterey.

The fact that some very odd things seem to have happened (OS downgrade when adding user?!) so far, is a further reason for a fresh start.

 

[thiasvm]

Thank you Mike. I will try that.

 

[hbmn]

Hi, thiasvm
I have the same problem. Were you able to resolve the problem? I bought a used Macbook Air 2017, all reset. As recommened above, I reinstalled the OS again (it does Mojave again, as it was the original OS).
Originally I had no intention to update (never touch a running system, as the saying goes) but it wouldn't let me use Keynote, hence my wish for the update. But it remains like that, "checking null":

Any suggestions/solutions/experience would be highly appreciated. 🙏
Best regards
hbmn

 

[thiasvm]

Hello HBNM. I did what Mike sugested. Simply follow the link he send and be patient, it took some time for the macbook to do it but it worked in the end. Now it works like it should

Best regards

thiasvm

 

[hbmn]

Hi
Thank you. I forgot to erase the HD first. Since I had Mojave installed, I installed Catalina first and then went on to Monterey so the jump wouldn't be too big (the Mac Hotline advised me on that).
Thanks to you all for your help, best regards
hbnm