Disaster Migrating From Mojave to Catalina on MacBook Pro (2015)

[drsteve]

Upgraded from Mojave to Catalina as several of my apps were no longer supported. The upgrade went well except that I could not connect to server even though I had wifi connection. In addition, I had several other glitches as I tried other programs. Very frustrated, I called support but that resulted in reinstalling Mojave from my Time Machine backup that was only 3 days old. The restore process appeared to go well and then bombed somewhere around 75%. I tried to restore several times and each time it the same result. The error message simply said "failed to complete".

Today when I tried to launch the machine all that appears is a folder with a ? mark inside. Restarted the machine while holding command and R and that takes me to mac OS Utilities where I tried again with no luck. However, while in the utility, I checked the drives and there were 3 showing up:
mac OS Base System (1.28GB used - 732.28 free);
Mac HD (152.24/GB used, 273.3 other volumes; and 73.53 free); and
Mac HD Data (nothing registers at all).

My MacBook Pro has 500GB storage and 16GB RAM.

At this point I am absolutely stuck and wondering if I should give up and purchase a new machine. I just don't want to believe that this can't be fixed as it was working very well before this saga began.

Please let me know if it can be restored or should I use it as an expensive door stop or paperweight.

Thanks for your help.

 

[Cory Cooper]

Hello and welcome.

This is a pretty good article: How to downgrade from macOS Catalina back to macOS Mojave

It may be best to totally erase the drive in the MBP, install Mojave using a USB flash drive created with DiskMaker X, then migrate from your Time Machine backup.

You shouldn't need to purchase a new machine, as long as there aren't any serious hardware issues. It doesn't sound like there are from what you have said.

Hope that helps,

C