- Plesk Onyx for Linux
When clicking the button "Update Core" at Plesk > Joomla! after selecting some instances, the button "Update extension" is shown as activated as well.
This bug with ID #EXTCERT-1995 in Joomla-toolkit which is planned to be fixed in next Joomla-toolkit updates.
This is a cosmetic issue and it can be safely ignored. Only core updates are executed when "Update Core" button is clicked.