Sorry to hear this.
WPML support answer:
I checked and I do not see this plugin on our official compatibility list, this means it was not tested by us and some issues may happen.
The best we can do is suggest to contact the author and report this issue, if they need our help they can join our compatibility program and we will be glad to help further.
Thanks for the answer but I will be verry happy If this great plugin find the way working with WPML. I think that problem isn’t that big and can be resolved.
Thanks again
Just disable mod_security option on your server…
Best regards
Thank you for your reply.
The problem is certainly in the server settings. I tested the same form on a different server with other hosting provider and everything works fine.