thank you for reaching out. My name is Lukas and I am a developer at WPML. I will take a closer look at this issue.
To help us troubleshoot more efficiently, could you please provide us with either a temporary access to the site or a Duplicator package? Additionally, any debug information you can share would be very helpful.
when I try to enter the URL you shared, I only get an 404 error. Do you have any security settings activated, which may block me from entering the WordPress backend? If yes, I would ask you to deactivate them. Maybe you could also provide us with a Duplicator Package of the site, so we can directly try to identify the problem on our system.
the login works now, thank you very much. Is it okay for you, if I will create a Duplicator Package of this site for us? This will help us to investigate the issue.
we’ve reviewed the issue on our end, but unfortunately we’re unable to reproduce it in our environment.
Could you please share the relevant PHP error logs from your server (especially from the time the issue occurs)? These logs will help us better understand what might be causing the problem on your setup.
as far as I understand the message from your provider, he has fixed the problem by resetting the .htaccess file. I tried this before, but without any success. As far as I understand you, this also did not helped and that is why you deactivated WPML? It would be very helpful for us, if you could provide us with the error logs from the website.
I would then suggest that you activate the plugin once more so we can make the error happen one more time. After this you may deactivate it again and we can take a look at the error logs. How does this sound for you?