To resolve this error it is must to have administrator access:
- Login to joomla admin panel.
- Here click on Extension << Manage << Discover
- After that click on “Discover” button which is on top left of the page and click on checkbox according to your choice.
- Click on “Install” button at top-left.
- You can enable them from Extensions >> Plugins and here you can find all plugins. Select checkboxes for plugins with “installer” name.
- Now you have to enabled them with “Enable” button.