Internet Account System Preference pane unable to load

There may be other issues, but you must fix at least the following.

A

Some of your user files (not system files) have incorrect permissions or are locked. This procedure will unlock those files and reset their ownership, permissions, and access controls to the default. If you've intentionally set special values for those attributes, they will be reverted. In that case, either stop here, or be prepared to recreate the settings if necessary. Do so only after verifying that those settings didn't cause the problem. If none of this is meaningful to you, you don't need to worry about it, but you do need to follow the instructions below.

Back up all data before proceeding.

Step 1

If you have more than one user, and the one in question is not an administrator, then go to Step 2.

Enter the following command in the Terminal window in the same way as before (triple-click, copy, and paste):

sudo find ~ $TMPDIR.. -exec chflags -h nouchg,nouappnd,noschg,nosappnd {} + -exec chown -h $UID {} + -exec chmod +rw {} + -exec chmod -h -N {} + -type d -exec chmod -h +x {} + 2>&-

You'll be prompted for your login password, which won't be displayed when you type it. Type carefully and then press return. You may get a one-time warning to be careful. If you don’t have a login password, you’ll need to set one before you can run the command. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.

The command may take several minutes to run, depending on how many files you have. Wait for a new line ending in a dollar sign ($) to appear, then quit Terminal.

Step 2 (optional)

Take this step only if you have trouble with Step 1, if you prefer not to take it, or if it doesn't solve the problem.

Start up in Recovery mode. When the OS X Utilities screen appears, select

Utilities ▹ Terminal

from the menu bar. A Terminal window will open. In that window, type this:

resetp

Press the tab key. The partial command you typed will automatically be completed to this:

resetpassword

Press return. A Reset Password window will open. You’re not going to reset a password.

Select your startup volume ("Macintosh HD," unless you gave it a different name) if not already selected.

Select your username from the menu labeled Select the user account if not already selected.

Under Reset Home Directory Permissions and ACLs, click the Reset button.

Select

 ▹ Restart

from the menu bar.

B

You installed the "Conduit" malware. Please take the steps below to remove it.

Triple-click the line below on this page to select it:

~/Library/Application Support/Conduit

Copy the selected text to the Clipboard by pressing the key combination command-C. From the Finder menu bar, select

Go ▹ Go to Folder…

Paste into the box that opens (command-V), then press return. A Finder window should open with a folder named "Conduit" selected. If it does, delete the selected item.

Repeat with these lines:

~/Library/Internet Plug-Ins/ConduitNPAPIPlugin.plugin /Applications/Toolbars

You may be prompted for your login password. Next, copy this line:

/Library

Select Go to Folder… again and paste. Don't delete the Library folder. Delete only the following items inside it, if they exist.

Application Support/Conduit

InputManagers/CTLoader

LaunchAgents/com.conduit.loader.agent.plist

ScriptingAdditions/ct_scripting.osax

Close the Finder windows you opened. Log out and log back in.

From the Safari menu bar, select

Safari ▹ Preferences... ▹ Extensions

Remove any extensions with the word "Conduit" in the description, and any others you don't know you need. If in doubt, remove all of them.

I installed OS X 10.10 (from 10.6) on my Mac Mini. When I started Apple Mail it said "Upgrading data" and soon quit. After deleting a number of preferences list files it eventually finished its "upgrade" and got to the "Add Account" stage. I entered the (old) Mail account information and got an "That account already exists" message.

I opened the Internet Accounts settings and deleted the (old) account. When I tried to add it back, I got the "Duplicate account" message. I deleted a number of PLIST files, resulting in "Unable to open Internet Accounts preferences pane." I continued to delete more files to no avail. Eventually I made the computer unusable, forcing a re-install from the CMD-R startup recovery utility. Still no mail.

After a lot of searching I found the post suggesting a file permissions change. I didn't know about the Terminal option, so the information was essential to getting my Mac working again.

I did both steps (command line and recovery utility). I was then able to delete the old Internet account, add it back in, log in, and get Mail working perfectly.

I would emphasize using the recovery utility "Reset permissions and ACLs" at the first sign of Mail trouble. It's very useful to learn about (or remind yourself about) the Command-R startup -- the recovery disk tools are extremely useful (essential).

I ran the first Terminal command in your reply and it resulted in "UID: User Undefined".

That's because you're running the tcsh shell. Did you take Step A2?

Back up all data before proceeding.

Triple-click anywhere in the line below on this page to select it:

~/Library/Preferences/MobileMeAccounts.plist

Right-click or control-click the highlighted line and select

Services ▹ Reveal in Finder (or just Reveal)

from the contextual menu.* A folder should open with an item selected. Move the selected item to the Trash. Log out or restart the computer and empty the Trash.

*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select

Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.