I've got the follwing screen:
I work with other 4 forms without any problem. I create this form modifying an other form, maybe it doesn't like it.
The test function doesn't work for this form.
I hope someone can help, I would like to avoid rebuilding it from zero.
It appears that somehow (probably through copy and paste) you've inserted a vertical tab character as the last character of your form's header. Due to a bug in our system, an error results. You can fix this by deleting this character from the header. I would suggest placing the cursor at the end of the header text and hitting backspace once. If you have trouble with getting this to work, please follow up by emailing firstname.lastname@example.org (you can address it to me) and I'll follow up with you directly and help you get the document working again.
Please let us know if my suggestion here fixed your problem.