This is a known issue of distributions using OpenSSL 3.x. It is caused by Qt being compiled
against OpenSSL 1.x libraries. At least for Ubuntu this can be changed by installing the
package libssl1 via a package search on the Ubuntu pages. The latest one known to me is the
package from Ubuntu 21.10.
I'm using Ubuntu 22.04 and just installed Eric7 using the recommended way in it's own environment. Starting Eric shows the following error.
Die angefragte Datei konnte nicht von https://eric-ide.python-projects.org/plugins7/repository.xml gedownloaded werden.
Fehler: Die Initialisierung von TLS schlug fehl
After that eric7 start's and seems to be working