The most common problem with Apache Server not starting is another Apache service running on the same port. To check this
- Quit MAMP PRO.
- Open the Activity Monitor located in your
- Type "httpd" into the search field on the top right.
- Quit every process you find after your search.
- Restart MAMP PRO.
If Apache still refuses to start check the log file available through the General Tab in you MAMP PRO interface for error messages.