@Html.BeginForm returns JSON results in one theme but not the default???

Hi,

I am completely puzzled... My NopCommerce 3.2 always returns JSON results when we click submit in a form generated by @Html.BeginForm from our theme but not when we switch to the default theme. I have no clue to where I should begin searching for the error? Anyone?

Finally we found it... One of the plugins we created was designed to return JSON. Because of this the entire page was set to return JSON, and therefore we got this strange behaviour.