My iMac has a warning box that pops up when I try to turn on that says keychain "login" cannot be found to store "registrationV1". It will not let me cancel or reset to defaults without popping back up. No other program will open either. If I try to open any program a warning box opens that says "Finder" can't be opened.
I have a time machine but don't know how to use it to start the computer from the latest backup either.
iMac (27-inch, Late 2013)
Try running Keychain Access/First Aid and resetting the original keychain.
Keychain Issues - Resolve see post by Kappy
If you've just changed your login password in Recovery mode, follow these instructions. Otherwise, see below.
At some point, you may have reset your keychain to default in Keychain Access. That action would have caused your login keychain to be renamed.
Back up all data before proceeding.
In Keychain Access, delete the login keychain from the keychain list. Choose Delete References when prompted, not Delete References & Files.
Triple-click anywhere in the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:
~/Library/Keychains
In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens (command-V), and press return. A folder will open. Rename the file "login.keychain" in that folder to something like "login-old.keychain". Rename the file "login_renamed_1.keychain" to "login.keychain". You can then close the folder.
Back in Keychain Access, select
File ▹ Add Keychain...
from the menu bar. Add back the file now named "login.keychain". If any of your needed keychain items are missing from it, also add back the file you named "login-old.keychain". I suggest you transfer any needed items from that keychain to the login keychain, then delete it. The transfers are made by drag-and-drop in Keychain Access. You'll need to enter your password for each item transferred.
iMac frozen
