Error message on long form

I have a roster form that is very long… 4 fieldsets; the second and third fieldsets have 20 sections each.

The form worked fine up until the 15th section; then I get the following warning (I am using Page Break but I’m still getting the error):

Warning: Invalid argument supplied for foreach() in /home/xxxxxx/public_html/wp-content/plugins/visual-form-builder-pro/includes/form-output.php on line 482

Any clues? I need all 20 spaces so I can’t shorten the form, unless there’s a maximum.

Thanks!

http://wordpress.org/extend/plugins/visual-form-builder/