No plugins show up after clicking "Install/Upgrade Plugins"

Your software
My Mautic version is: 3.1.2

Your problem
When i go to “Gear icon” -> Plugins and click on “Install/Upgrade Plugins” nothing happens. As from the documentation i expected that other plugins will show up now. Is the way changed with the new version? Do i need to download them separately?

could u attach a screenshots?

Yes, but there is nothing to see than the two default Plugins “OneSignal” and “Twilio”. In der /plugins folder of the docroot i see:
-rw-r–r-- 1 www-data www-data 118 Oct 29 10:03 index.html
drwxr-xr-x 17 www-data www-data 4096 Nov 4 16:42 MauticCitrixBundle
drwxr-xr-x 12 www-data www-data 4096 Nov 4 16:42 MauticClearbitBundle
drwxr-xr-x 9 www-data www-data 4096 Nov 4 16:42 MauticCloudStorageBundle
drwxr-xr-x 15 www-data www-data 4096 Nov 4 16:42 MauticCrmBundle
drwxr-xr-x 9 www-data www-data 4096 Nov 4 16:42 MauticEmailMarketingBundle
drwxr-xr-x 16 www-data www-data 4096 Nov 4 16:42 MauticFocusBundle
drwxr-xr-x 13 www-data www-data 4096 Nov 4 16:42 MauticFullContactBundle
drwxr-xr-x 6 www-data www-data 4096 Nov 4 16:42 MauticGmailBundle
drwxr-xr-x 7 www-data www-data 4096 Nov 4 16:42 MauticOutlookBundle
drwxr-xr-x 17 www-data www-data 4096 Nov 4 16:42 MauticSocialBundle
drwxr-xr-x 4 www-data www-data 4096 Nov 4 16:42 MauticZapierBundle

But even that is too less, i guess. When i hit the “Install…” button on the plugin page, a very short progress bar is shown but nothing changes. Could this be due to some missing proxy configuration to access internet?

I found out the it was a known problem. After changing the default db_server_version from “5.5” to:
'db_server_version' => '5.7',
the plugins loaded, or at least they are shown after hittin the “Install…” button.
But when i click on an plugin i again wait forever and nothing happens.

The only changes that would occur beyond the standard Mautic Plugins is based on manually loading a new plugin into your plugins directory and clicking the button to refresh your available plugins. Clicking that button does not give you a new assortment of plugins. Would be cool if it did.

If this a fresh install or a copy of an existing install?

I’ve installed Mautic from source on a Debian machine. After i ran into other troubles i decided to restart installation. I think my mistake was to fetch the zip directly from the Github repo. In the second try i downloaded it via the webform on mautic.org/download It was also a bit confusion with the version numbers, but the one come from the download is 3.1.2 also. Now the system itself runs again and the db-version was already set correctly to “5.7” but still no plugins shown after clicking the “Install…” button.