I wanted to reinstall the plugins via the "discover" button, but they do not appear there at all.
Do you have any suggestions how I can reinstall the install-plugins manually without the discover-button?
Thank you very much for your support in advance!
UPDATE
And if I click on Extensions/Install - there is this message displayed:
Warning
No installation plugin has been enabled. At least one must be enabled to be able to use the installer. Go to the Plugin Manager to enable the plugins.
But in the plugins manager there are absolutely no install-plugins to be found - nor in the "discover" folder