Using the PHP settings link to go to the page containing PHP detailed information (phpinfo).
Errors
Performance Monitor: PHP Error Log page (Settings > Performance > PHP errors (N)) contains PHP error log, where N - general number of errors.
Note: this page is shown only if the Performance monitor module settings specifies Log PHP warnings.
Log PHP warnings is stored in the database. You can delete PHP warnings log using the option
Clear existing monitor statistics (when saving this form)
Available only when monitor is disabled