Both mojoPortal and Form Wizard Pro need to use the same version of NeatUpload. The new version of mojoPortal released today uses a newer version of NeatUpload, so I also made a new release of Form Wizard Pro today which also uses and requires the new version of NeatUpload.
So, to solve this problem make sure you upgrade both. From the error, it sounds like you installed the new Form Wizard but have not upgraded to the new mojoPortal or vice versa.
Hope it helps,
Joe