My SharePoint Site gives an error and doesn't load...

Parser Error
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.

Parser Error Message: This page has encountered a critical error. Contact your system administrator if this problem persists.

Source Error: ....
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Some Solutions.. May solve the problem

1. Maybethe *.resx files have some strings missing,please check the server event viewer and 12\log files.  Also try an iis restart.
2. Web.config file got corrupted with "?" characters at random places in the file.(the question mark character   just got added on 12 different lines in the config file.)
       Fix:Removing those question markssolved the problem.
       So check if your web.config file is corrupted.
3. Assembly registered in the SafeControl-section referenced a non-existing assembly, and therefore the SafeMode did not start successfully.
   For detailed information about the error, you should have a look into the Application Event Log, where a detailed error message should be shown.