Resolved Let's Encrypt Certificate invalid? failed to load resource: net::err_cert_common_name_invalid

[ukeller66]

10 days ago I installed a new Server and move my one of my Domains https://www.optiliga.de to this installation. I saved this via plesk with a 'Let's Encrypt' certificate.
All works fine.
Yesterday I looked to the domain and see, it is broken. In console log I find the message "failed to load resource: net::err_cert_common_name_invalid". I checked all and cant finde the failure.
Has anyone an idea, where to seek?

 

[IgorG]

I think this problem is addressed in the following KB - Website shows warning: ERR_CERT_COMMON_NAME_INVALID/SSL_ERROR_BAD_CERT_DOMAIN

Does this solve your issue?

 

[ukeller66]

No, not really. After I looking around a little bit, making some experiments with missing TXT-Records, I found the solution.

All CSS, JS, images and so on was loaded with 'https://www.optiliga.de/{the file}'. However, the name of the certificate is correct 'optiliga.de'. After I change the prefix to "'https://optiliga.de'" all works fine.

The question only is, whats the reason, that the old (wrong) version works before (At least some days)?
Anyway, never touch a running system.

Thanks for your support.

 

[ukeller66]

PS: How can I close / set to solved the thread?