Nov 25th, 2016, 2:34 PM
Definitely late for the OP but I had this same issue with an external form and was able to resolve it. The problem arises because the PHP is correctly calling an array to pass on during processing but the FT interface offers no mechanism to create the array.
Maybe that sounds too technical but the solution is easy once the maddening process of finding it is achieved.
In your form HTML simply add empty brackets to the end of your name attribute in your checkbox input tag.
Example: <input type="checkbox" name="examplename[]" value="examplevalue">
This ought to greatly help anyone who finds this thread when they encounter this same issue and need a solution.
Maybe that sounds too technical but the solution is easy once the maddening process of finding it is achieved.
In your form HTML simply add empty brackets to the end of your name attribute in your checkbox input tag.
Example: <input type="checkbox" name="examplename[]" value="examplevalue">
This ought to greatly help anyone who finds this thread when they encounter this same issue and need a solution.