How to recover keychain

By the way, I had another problem with keychain when doing another migration. I couldn't sign into icloud properly. I was on the phone with apple for a long time. I had to wipe the computer a couple times and migrate data.

In the end, I got it fixed. There were 2 things that may have fixed it. Hopefully this info helps those who may have a similar issue.

The 2 things i did before it suddenly worked:

#1: was resetting the NVRAM.

#2: I made sure that the new computer I was migrating to had a different unlocking password than the computer I had migrated from.

I think #2 helped because on previous tries, the Mac would prompt me for the password for my other Mac that was connected to icloud. And so I would type it in, but the mac would say "no that is your password for THIS computer ... you need to type in the password for the other mac" or something similar. And so I think it got confused because the passwords were the same.

So try those 2 things if you have trouble signing into icloud after using a time machine backup to migrate to a new computer.

Ok I have chosen yesterday to inherit the backups. However, the drive has been "Preparing..." to do a back up ever since then and has not completed a backup even though it has been Preparing for 10 straight hours.

Perhaps it has run out of space. I saw that it says 100GB available. Though I am certain that the previous mac's backup was around 1.35TB in size, and so there should be 0.65TB left (650GB). Not sure what's going on there.

I'll try to let it finish Preparing and do a backup. Once that is done, should I be able to finally access those folders that I don't have access to?