Failed to verify certificate - certificate signed by unknown authority

[studero]

Hi,

I use the template Website certificate by Zabbix agent 2 to verify the validity of the certificate. But on one of my test, I have the following error message :
{"value":"invalid","message":"failed to verify certificate: x509: certificate signed by unknown authority"}

But I made the same check with differents sub domain, and that's works correctly.

I need help!

Regards
Olivier