Q: Just started getting a message on Yosemite about cannot connect to a server I removed months ago.

There are many possible causes for this issue, and it may be very hard to resolve without wiping your account clean of everything except documents as a last resort. Please take each of the following steps that you haven't already tried. Back up all data before making any changes.

If you get the alert in the login screen before you log in, stop here and ask for instructions.

Step 1

If you get the alert as soon as you log in, it's probably caused by one of your login items or by software that otherwise loads at startup or login. Ask if you need help identifying it. Known offenders are "1Password" and "Adobe Resource Synchronizer."

Step 2

If there's an icon representing the server in the sidebar of a Finder window, hold down the command key and drag it out.

Step 3

In the Finder, press the key combination command-K or select

          Go ▹ Go to Server...

from the menu bar. In the upper right corner of the window that opens is a Recent Servers popup menu represented by a clock icon. From that menu, select

          Clear Recent Servers…

and confirm. Test.

Step 4

Open the Printers & Scanners pane in System Preferences and delete any network devices you no longer use. If in doubt, delete them all and add back the ones you want.

Step 5

Triple-click anywhere in the line below on this page to select it, then copy the text to the Clipboard by pressing  command-C:

~/Library/PDF Services

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. A folder may open. If it does, move the contents to the Desktop, or to a new folder on the Desktop. Log out and log back in. Test. If there's no change, put the items you moved back where they were and continue.

Step 6

Open the folder

~/Library/Preferences

as in Step 5 and move the file named "loginwindow.plist" items in that folder to the Trash, if it exists (it may not.)

Log out and back in again, and test.

Step 7

Other possible causes are references in the iPhoto, iTunes, or iMovie library pointing to the server, bookmarks in the Preview application, and PDF files created by Adobe Acrobat with embedded scripts.

Try rebuilding the iPhoto library, if applicable.

Step 8

Resources such as images or sounds stored on the server may have been added to various applications. Examples would be pictures added to Contacts and custom sounds added to Mail. The range of possibilites here is practically infinite, so I can't be more specific. You might get a hint by launching the Console application and looking for error messages that appear at the same time as the alerts.

Step 9

Disconnect all wired peripherals except those needed to start up. Start up in safe mode. Test. After testing, restart as usual (not in safe mode) and verify that you still have the problem.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a Fusion Drive or a software RAID, you can’t do this. Ask for further instructions.

Step 10

Launch the Directory Utility application. Depending on what version of OS X you have, you may be able to do that by entering the first few letters of its name in a Spotlight search. If that doesn't work, triple-click anywhere in the line of text below on this page to select it:

/System/Library/CoreServices

Right-click or control-click the selected text and select

          Services ▹ Open

from the contextual menu.* A folder named "CoreServices" will open. The Directory Utility application is in that folder, or in a subfolder named "Applications".

In the Directory Utility window, select the Directory Editor tool in the toolbar. Select Mounts from the Viewing menu in the toolbar, and /Local/Default from the node menu, if not already selected. On the right is a list of names and values. By default, the list is empty. If it's not empty, post a screenshot of the window and stop here.

*If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). Open a TextEdit window and paste into it (command-V). Select the line you just pasted and continue as above.

Step 11

Open the following file as you did in the last step:

/etc/auto_master

It will open in a TextEdit window. The contents should be exactly this:

#
# Automounter master map
#
+auto_master          # Use directory service
/net               -hosts          -nobrowse,hidefromfinder,nosuid
/home               auto_home     -nobrowse,hidefromfinder
/Network/Servers     -fstab
/-               -static

If there are any other lines in the window, post them. Otherwise, close the window.

You may have one or more links to a disused server in the Photos library. Since the server is no longer accessible, those links are now invalid. You should be able to find them by a tedious process of elimination. First, back up all data.

Select about half of your photos and start to drag them. Don't actually move them anywhere; just drag them a little and release. If you get the warning, then some of the photos you selected are invalid links. Narrow down the selection. If you don't get the warning, select the other half of the library.

When you've isolated the invalid items, delete them and then select

          File ▹ Show Recently Deleted

from the menu bar. Delete the items permanently.

(Credit for this idea to Winston Moy of winstonmoy.com.)

When you get the alert, note the exact time: hour, minute, second.  

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

The title of the Console window should be All Messages. If it isn't, select

          SYSTEM LOG QUERIES ▹ All Messages

from the log list on the left. If you don't see that list, select

          View ▹ Show Log List

from the menu bar at the top of the screen.

Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.

Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.

Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.

The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.

Please don't indiscriminately dump thousands of lines from the log into this discussion.

Please don't post screenshots of log messages—post the text.

Some private information, such as your name, may appear in the log. Anonymize before posting.

When you post the log extract, you might see an error message on the web page: "You have included content in your post that is not permitted," or "The message contains invalid characters." That's a bug in the forum software. Please post the text on Pastebin, then post a link here to the page you created.

Do you have any idea what was on the server that could be related to the content on the phone? Did you store an iTunes library on it?

How to re-create your iTunes library and playlists

Rebuilding an iTunes Library: How to Do It & What to Expect

Glad to hear it.