Support

I suspect that your host made a configuration change on their servers which causes them to throw this error when you submit the configuration form. You need to contact your host about that.

My crystal ball says that they do not like the fact that our configuration form sends a POST request with a JSON document instead of a typical www-url-encoded format. We have to do that because we have approximately 110 configuration parameters on the configuration form, whereas a lot of other hosts put a hard limit on 100 parameters in a form. If I am guessing the problem right (remember, I am consulting my “crystal ball”, i.e. my experience on unintended consequences of well-meaning changes made by systems administrators over the last 20-odd years) your host should be able to add an exemption for our configuration form; the URL path where the form is POSTed is always the same, and there are two distinct parameters (page and view) they can use to create a very specific exemption with their configuration.