One of the system requirements for Mighty Extensions components is FTP mode set up properly.
You can find FTP mode settings in joomla Global Configuration -> tab Server -> FTP settings.
FTP mode must be enabled and well configured, i.e. you need to indicate the same ftp user as all the files and folders of your joomla project have. If you indicate a wrong FTP user then you may get a lot of errors during components installation/update. For instance:
"Error! Could not find a Joomla! XML setup file in the package."
Thus before installation/update of any component you need to make sure that:
- FTP mode is ON in joomla Global Configuration.
- Correct (see above) FTP user is set in FTP mode settings.