Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
there is an error. But that error doesn't produce this error message.
You have a DNS entry www.evoo2.commerceowl.com. This www-subdomain doesn't work with your certificate, because a *.commerceowl.com works only with three domain labels, not with four.
But connecting that subdomain doesn't work, there is a SendFailure - error, the webserver closes the connection. FireFox has PR_END_OF_FILE_ERROR, Chrome shows a ERR_CONNECTION_CLOSED.
That's an error (solution: Remove your www entry), but not the situation of your error. There are no other errors visible (mixed content).
Well… At a guess, there’s web filtering software installed on the computer / network / DNS resolver, and your (sub)domain is being blocked.
Presumably, blocked websites are MITMed with some web page that provides more information.
You might try accessing the site over HTTP, or clicking through the security warning in private browsing mode – with the attendant risks, of course.
At best, your domain is accurately categorized but the network is configured to block broad categories of legitimate domains (like “e-commerce” or something). At worst, the domain is miscategorized as malicious.
By nature, TLS stops MITM attacks even when they’re “benign”. In something like a corporate environment where the IT department has full control of the computers, they can install a custom root CA or custom software so that the block page can load without a certificate error. Maybe this network doesn’t, or it’s misconfigured.
(Or perhaps it’s a different sort of MITM attack disguised as “legitimate” web filtering.)
Thanks for the tip!