hello,
I don't know if this thread is still open but I just want to say that I faced the same problem and I was able to fix it. Connect to your ftp server and navigate to the mamblog sub-folder under components. It looks something like this: /public_html/.../components/com_mamblog. Find the file configuration.php and set the permission on the file to 766. You can do: chmod 766 configuration.php if you're using the command line. If you're using a FTP client like FileZilla, right-click on the name of the file and click on file permission to set the value to 766.
I thought this might help someone save sometime.
Best regards,
ramadji