VitexSoftware/abraflexi-reminder

AI Summary: The AbraFlexi reminder application throws a `TypeError` because the `file_exists()` function receives a `null` value instead of a string as the filename argument on line 107 of `RemindMailer.php`. The task is to debug and fix this error, likely by ensuring that the filename variable is properly populated before being passed to `file_exists()`. This involves examining the code around line 107 to identify the source of the `null` value and correcting the logic to provide a valid filename string.