Ihave spoken with the hosting and this was their reply:
Im having an issue setting up the WPML translation plugin on our site and their support team has suggested i set the header to: add_header X-Content-Type-Options nosniff; how can I do this?
Christian : You can only switch it on or off: hidden link
me -> what does that mean? what is the default
Christian : Default is on
me : have you expereinced issues with WPML plugin? it
Christian : No, we have many customers who use it.
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So I created a new blank installation in my hosting without any other plugins and the WPML setup worked, therefore it cannot be related to the X-Content-Type-Options.
Could this be database related? I have debug the issue with our hosting support and the blank site installation working would rule out it being server related.
In that case, I would suggest starting the installation of the plugins on your website from WPML first and then the others one by one keeping track of whether the issue will happen again.
That would help check if it might be related to any possible plugin/s conflict.