Warning: require(./includes/startup.php): Failed to open stream: No such file or directory in C:\Apache24\htdocs\forums\common.php on line 19

Fatal error: Uncaught Error: Failed opening required './includes/startup.php' (include_path='.;C:\php\pear') in C:\Apache24\htdocs\forums\common.php:19 Stack trace: #0 C:\Apache24\htdocs\forums\viewtopic.php(17): include() #1 {main} thrown in C:\Apache24\htdocs\forums\common.php on line 19