The PHP function strpos($haystack, $needle, $offset) is designed to find the numeric position of the first occurrence of a substring within a string, where the haystack represents the string to search and the needle is the substring being sought. A common issue arises when the needle is an empty string, triggering an E_WARNING: strpos(): Empty needle warning. To prevent this warning, it is advised to perform a check ensuring the needle is not empty before invoking the function. By incorporating this validation, the warning can be successfully avoided, allowing normal code execution. Additionally, tools like Rollbar can assist in managing and analyzing errors in real-time, thus streamlining error handling and improving the deployment of production code.