If you look at crt.sh | meteo-cham.ch you can see there's a still valid certificate issued most recently 2023-05-24, still valid for about a month. Which would be due for renewal actually. But your webserver is still using the previous one issued on 2023-04-22.
So you actually have gotten issued a valid cert, but you're not using it. And that one is also up for renewal.
To advice you further, if required, we really need the answers mentioned by @linkp.
I used c ertbot to create the certificates and configure the apache. Everthing went well without errors. I checked the httpd.conf file and the etc entries. Could not identy discrepencies. However, apache does not activate ssl. I'm stuck . . . Any helpful hint?
My domain is:
I ran this command:
certbot . . .
It produced this output:
all certificates required
My web server is (include version):
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know):
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): the most recent version available for download
Certbot is not the best ACME client for Windows; As it doesn't integrate well with Apache [for Windows].
That said, you should be able to use "certbot certonly" and afterwards just "certbot renew" [combined with some method to reload Apache] to keep your web service secure.
Thanks for the hints! After restarting the apache this morning I've got error messages telling that the cert files where either not found or being empty. . . then I inspected the different config files and directories, renamed the cert-files and applied changes in the config, now everything works again as expected. You saved my day!!