Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
The APS Catalog has been deprecated and removed from all Plesk Obsidian versions. Applications already installed from the APS Catalog will continue working. However, Plesk will no longer provide support for APS applications.
Please be aware: with the Plesk Obsidian 18.0.78 release, the support for the ngx_pagespeed.so module will be deprecated and removed from the sw-nginx package.
I've just had this same error on setup of a first time key. It turned out that Plesk does not like spaces in the label at the end of the key.
i.e. the key ended in "New Key for MySite" and I had to change it to "NewKeyforMySite" - once I did that, the key manger page worked,
For anyone else looking for the mysterious icon, it's top right and used to expand/collapse the right hand panel.
There are screenshots in this thread: Resolved - How to work with SSH Keys Manager