This article offers tips for troubleshooting system errors of Type 1, Type 2, and Type 3.

Symptom

An application stops responding, and the following error message is displayed: "Sorry, the application 'Application Name' unexpectedly quit because an error of type (1, 2, or 3) occurred."

Products affected

• System software versions 7.0 through Mac OS 9

Solution

Type 1, 2, and 3 errors are Mac OS memory-addressing errors. These are usually caused by incompatible software or software conflicts.

System software compatibility issues usually occur with older software. If your software falls into this category, contact the software vendor for an updated version of the software that works with your installed system software version.

Software conflicts most often involve faults with extensions and control panels. Depending on which version of system software you have, you can troubleshoot these items in the following way:

System 7.0 to System 7.1.2

1. Restart your Macintosh computer with the Shift key held down until you see the message "Welcome to Macintosh, Extensions off". This procedure temporarily turns off all non-essential extensions and control panels.

2. Try to recreate the failure. If the failure does not reappear, then you have an extension conflict. Go to Step 3.

• If the failure continues to occur it is probably not related to any third party extension or control panel. You may need to contact the software vendor to upgrade your application.

3. To determine which of your extensions or control panels is causing the failure, create a folder on your desktop and place all your non-Apple extensions and control panels in that folder and restart your computer.

4. One by one, place the items back into your System Folder, restarting and attempting to recreate the failure every time you add an item. When the failure reoccurs, then you know that either the last item you added, or a combination of the items you have added, is causing your conflict. Contact the vendor of the extension or control panel to see if there is an updated version available.

1. Restart your Macintosh and hold down the Space Bar until the Extensions Manager control panel opens.

2. Use the pop-up menu in the Extensions Manager to choose "All Off". Close the Extensions Manager control panel.

3. Try to recreate the failure. If the failure does not reappear, then you have an extension conflict. Go to Step 4.

• If the failure continues to occur, it is probably not related to any extension or control panel, you may need to contact the software vendor to upgrade your application.

4. Restart your Macintosh and hold down the Space Bar until the Extensions Manager control panel opens. Turn on groups of extensions and control panels by clicking to the left of each item to put a checkmark by the item. Close the Extensions Manager control panel.

5. Try to recreate the failure.

You can attempt to remedy a conflict by changing the loading order of a given extension or control panel by locating the file in the System Folder and adding a space or spaces to the front of the file's name. There are also third party utilities that allow you to test and manage extensions and control panels.

For related information on troubleshooting Type 1, 2, and 3 System errors, please see article 30725: " Macintosh: Random Behaviors When No Printer is Chosen "