The reason why you hit the error message is because your upload_max_filesize was at max 2mb so you need to change your maximum file size allow to 2 instead of 8 http://take.ms/xaay3
It could most likely be caused by changes from your hosting provider or if you have added any .ini settings file. You can view your php information from https://mahiber.com/administrator/index.php?option=com_admin&view=sysinfo and clicking on the "PHP Information" tab. Just search for the value upload_max_filesize