A syntax error usually occurs when you have added extra code in WordPress and accidentally missed something or the code has the wrong syntax. This will result in a PHP parse error and you will see a message like:
Parse error- syntax error, unexpected $end in /public_html/site1/wp-content/themes/my-theme/functions.php on line 278
The error message indicates where the error was found in the code with a line number. To fix this problem you need to have the syntax corrected.