Apple Mail database upgrade screen appears at Mail startup

Some things you can try.

Mail Upgrade message in Mavericks won’t go away – Welcome to Mail

Mail Upgrade message in Mavericks won’t go away – Welcome to Mail (2)

What type of account(s)? (POP, IMAP, Exchange)

Do you have any messages stored locally under "On My Mac"?

Note: Yosemite uses the V2 folder and El Capitan uses V3. There are issues with the upgrade and more so if you try downgrading. Once I know what type accounts you have we can discuss a clean restore to Yosemite Mail.

Have you reverted to Yosemite?

If yes...

Quit Mail

Go to System Preferences > Internet Accounts

Uncheck Mail for each account.

Go to User's Library (see below)

Scroll down to Containers. Delete the com.apple.mail folder

Scroll down to Mail. Rename Mailxxx

Log out under the Apple in the Menu bar

Login

Delete the Trash

Open System Preferences > Internet Accounts

Check Mail for your IMAP account. (If you have multiple accounts, I suggest letting each account download completely before adding your other accounts.)

While the messages are downloading, do you see the folders being created in V2?

If yes, make sure all folders are assigned correctly for the default folders (Inbox, Drafts, Sent, Deleted Items)

Next, add other accounts.

If you had messages stored locally, we can go back into Time Machine to restore.

If no, start again with steps above then also remove these files:

Accounts folder

Preferences folder:

.../Preferences/com.apple.accounts.plist (file)

.../Preferences/com.apple.accountsd.plist (file)

.../Preferences/com.apple.mail-shared.plist (file)

.../Preferences/com.apple.MailMigratorService.plist (file)

.../SyncedPreferences/com.apple.mail-com.apple.mail.vipsenders.plist (file)

.../SyncedPreferences/com.apple.mail.plist (file)

Show User's Library

The User's Library folder is hidden by default. To unhide: Select the Finder in the Dock. Under Go in the Menu bar > hold down the Option key and you’ll see the Library.

Finding the User Library Folder

http://www.takecontrolbooks.com/resources/0167/site/chap11.html#FindingtheUserLi braryFolder

Let's do a quick test in a new User or the Guest User.

CREATE A NEW USER

Go to System Preferences --> Create a New User in Users & Groups.

Switch to the New User by logging out under the Apple in the Menu Bar.

Log into the new User.

You can skip logging in with an Apple ID. Hit continue then skip.

Does System Preferences open correctly? Try other features that are not working for you since you reverted.

Let's go over your options, but first please answer the following:

1) How much available space on your drive? How much space used? Use Disk Utility in Applications/Utilities to find this info.

2) Do you have an external drive that has Time Machine? Do you have enough space on the drive to do a clone backup? Please verify using Disk Utility that the disk is formatted as GUID.

Select the top drive in Disk Utility. You'll see partition map scheme in bottom right.

Options:

1) move all your data over to the new User.

2) erase your drive and install Yosemite clean then manually bring over your data

3) rebuild the broken User folder

4) erase your drive and install El Capitan not that it is at the final version 10.11.5 and manually bring over your data.

First, you want to clone your current drive. Don't skip this step! If there is a problem you can boot from your clone and be right back to where you were before you started. You can't boot from Time Machine.

You can create a partition on the external drive that is large enough to copy your data plus some free space. If you don't know how to partition, see directions here: How to partition an external drive using Disk Utility

Use SuperDuper to clone the drive. It's free to do the erase and clone for the first step. If you want scheduled backups that are smart backups not a full erase and clone you can purchase for $27.95.

Second: Rebuild broken User:

If you did not create the test User as Admin, set as admin in System Preferences. Unlock to make changes.

(note the exact user name, short name, and password for the broken user.)

Log out under the Apple in the Menu bar

Log in to test admin user.

Open System Preferences > Users & Groups

Unlock to make changes

Select the broken User, then click on the minus sign to delete it. Select "Don’t change the home folder" to leave the account's home folder as is, in its current location inside Users folder. Continue by clicking "Delete User". This way you have deleted the user account but you have preserved all its local data and preferences.

Now, add a new account by clicking on the + sign.

Use the EXACT user name, short name and password.

The system will detect the existing home folder. You'll get a popup dialog warning. Select "Use Existing Folder".

After the setup is complete, the account will be restored.

Log out of the test User and into your old User.

Test to see if the problem is solved.

If you still have problems, you can move to the new User. See Move your data to a new User or a new Mavericks partition

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