Five months I have reported a bug here:
http://www.gravityhelp.com/forums/topic/bug-report-invalid-argument-with-form-display
But, the problem is not gone, only it has moved to another line (code changes in that file in recent versions). So, here it is again, my server error log is full of these:
PHP Warning: Invalid argument supplied for foreach() in /....path.../wp-content/plugins/gravityforms/form_display.php on line 1608
I am using latest 1.6.12 version.
Regards,
Milan