Hi,
As discussed on the 2.3.6.1 release notes, an update of Form Wizard Pro 0.0.2.3 was released at the same time as mojoPortal 2.3.6.1 to solve this problem.
Make sure you do have mojoPortal 2.3.6.1 installed, check under Administration > System Information
You can download the latest Form Wizard Pro by clicking the "My Account" link at the top of the page and then click on Order History.
Hope it helps,
Joe