Php Warning: Strpos

Hi guys I have checked the logs and found the error as one below

PHP Warning:  strpos(): Offset not contained in string in /var/www/html/app/functions/fn.common.php on line 2159

Any clue what is going on please?

Thank you

I seen tool have similar last year

https://forum.cs-cart.com/topic/51879-php-warning-strpos/