If the front end activation dialog box appears when you launch Wolfram, either Wolfram could not locate the mathpass file or there was no valid password in the mathpass file. To resolve this problem, first check that there is a mathpass file in one of these directories: $BaseDirectory\Licensing, $InstallationDirectory\Configuration\Licensing, or $UserBaseDirectory\Licensing. If you did not find a mathpass file in these locations, follow the instructions in "Activating Mathematica" to reenter your password.

If there is a mathpass file in one of those directories, the password or passwords are invalid. Make sure that your MathID number matches the MathID number used to issue your password. If your MathID number changes, you will need to contact Customer Service to get a new password. Contact information is provided in "Registration and Passwords".

Front end preferences, such as the locations of recently opened and saved files, are stored in a front end initialization file called init.m. This file is located in $UserBaseDirectory\FrontEnd. The default value of $UserBaseDirectory for different platforms is listed in "Configuration Files". To find the exact location of this directory on your machine, evaluate the command $UserBaseDirectory in a notebook.

If you need to reset the front end preferences to their default values, hold down Shift+Ctrl during startup. This will cause the initialization file to be rebuilt automatically.

Information about your Wolfram System system layout, such as the locations of text resource files, is stored in caches. These caches are located in the following locations:

A corrupted cache may cause the front end to produce an error or quit immediately on startup. To restore the caches to their default values:

This will cause the Wolfram System caches and the initialization file to be rebuilt automatically. If you want to rebuild your caches but retain your preferences, hold down Shift during startup. This will delete and rebuild the cache without rebuilding your front end initialization file.

Make sure that the fonts are installed on the machine that displays the front end or on a font server.

If you see the error xset: bad font path element, either the fonts are not properly installed on your machine, or your font path is too long and exceeds the allowable limit. Make sure the fonts are properly installed, or copy the fonts to a directory that is already on the font path.

For further assistance, check the Technical Support FAQs on the web at support.wolfram.com. If you are a Site License Administrator, additional Site License Documentation is available at site.wolfram.com. If you do not find the information you need, please contact Technical Support by sending email to support@wolfram.com or by calling +1-217-398-6500. Include your license number in all correspondence. Your license number is located on your electronic or physical copy of the license certificate. It is also available after installation by going to the Help menu and clicking About Mathematica. You must be a registered user in order to receive installation support. You must have a current Premier Service subscription to receive Technical Support.