Thread:Project:Support desk/Sudden PHP Parse error & PHP Fatal Error MWDebug.php & GlobalFunction.php

Please help,

My wiki page (latest version) is suddenly white and the error log produces two errors:

[19-Apr-2015 22:58:58 America/Chicago] PHP Parse error: syntax error, unexpected '|' in /wiki/includes/debug/MWDebug.php on line 341 [19-Apr-2015 22:58:58 America/Chicago] PHP Fatal error: Class 'MWDebug' not found in /wiki/includes/GlobalFunctions.php on line 981

Prior to that the wiki has been running without a hitch the last error was over a month ago for the autodiscovery mechanism issue with skins (I resolved that)

I'm a total novice with PHP, so any insight would be greatly appreciated. The wiki is used for commercial purposes so it has put us at a stand-still.