How to increase the PHP memory_limit for better performance?
Occasionally, you may encounter the following error: Fatal Error: Memory Size Exhausted? Or Perhaps your website has just gone blank? Installing a new theme, adding a plugin, or upgrading your WordPress version usually causes this problem. Is the site running too slowly or is the server overloaded? Your host's PHP memory_limit is less than what your process requires. This is the main cause of this error. If this occurs, you'll need to increase the host memory limit in order to complete the process.