As you say the issue only occurs on this site as your other sites work fine. This leads me to suspect the issue is the site itself.
Also was the SSL issue addressed?
Finally remember that if the SSL only covers 1 domain then only that domain will have a valid certificate. If it is a sub domain then the SSL validation will fail.
The test sub domain still doesn't have a valid certificate. If you take a look at my screenshot
You will see the Not Secure message in my browser.
What this essentially means is the the Certificate is not valid. Given that it works on the main domain but not the Sub Domain then this needs to be resolved.
This is essentially the same wordpress instance with the only difference being the ssl certificate validation.
Thanks for this site I was able to see that the error here is being thrown
Parse error: syntax error, unexpected 'if' (T_IF) in /var/www/vhosts/latraco.eu/httpdocs/wp-content/plugins/types/vendor/toolset/toolset-common/classes/validation-cakephp.php on line 543
This warrants some further investigation, but i'm unable to create a copy of the site to do the further checks.
I do however notice that your version of wordpress is outdated and this is one of the steps that I would've taken to see if it would resolve the issue.
Secondly I would try to disable all the non-toolset plugins on this site and check back to see if the error remains. Given the nature of the error a report to our team would be needed but I would need to ensure that the issue doesn't occur on the latest version of wordpress or with all the non-toolset plugins disabled.
If you're able to quickly confirm that the issue still remains then we can go from there.
You can use the site hidden link for this, same login as latraco.eu.
Same set up as xtrawarmled.com
This is a test site so here you can disable all the non-toolset plugins.
The problem is that this test site's issue is completely different from the one with the fatal error issue.
Using that site would not give us a true representation of the actual issue at hand. On the test site i can say the issue is with the SSL certificate but on the hidden link the SSL is working correctly.
I do however see the same error 500 on the async-upload.php file. What I need for you to do for me is to update to the latest version of wordpress. Version 5.4
I would like to ensure that before we proceed we are running on the latest version of wordpress. I will see how best I can work with the test site.
Given that its a multi-site instance updating wordpress will update it for all your sites.
