Warning: require(C:\/functions.php): failed to open stream: No such file or directory in C:\inetp on line 5

Fatal error: require(): Failed opening required 'C:\/functions.php' (include_path='C:\inetpub\wwwroot\psainsurance\web\vendor/pear/pear_exception;C:\inetpub\wwwroot\psainsurance\web\vendor/pear/console_getopt;C:\inetpub\wwwroot\psainsurance\web\vendor/pear/pear-core-minimal/src;C:\inetpub\wwwroot\psainsurance\web\vendor/pear/archive_tar;.;C:\php\pear') in C:\inetp on line 5