Problem creating new bill - by: mklfontaine

Hello,
Please can somebody guide me to overcome this issue.
I can't create bills. I get the following error message :
Erreur sur submitForm('../tool/saveObject.php', 'resultDiv', 'objectForm') :
Le formulaire '${3}' n'est pas un 'widget'.

I try to reinstall everything and i've upgraded to V6.4.3
Thank you in advance