If the error message Fatal error: Allowed memory size of x bytes exhausted occurs during a website development project within a Joomla installation, it does not necessarily have to be caused by the PHP configuration or an insufficiently low memory_limit setting.
If the memory limit has already been increased sufficiently and the error continues to occur, the cause may be a corrupted file system — for example, if the index.php from the root directory was copied into a template directory and overwrote the existing index.php there. If it is no longer possible to determine which files are corrupted, reinstalling the Joomla project is usually the most reliable solution.
