Cannot run Forms with ebs R12

Hi,

I've performed a new install of R12.1.1.
After logging ebs, i would like to access the "Define profile options" program.
But, the "Oracle Developer Forms Runtilme - Web" doesn't work. It's a matter of jinitiator i think.
This is the error message :
"FRM-92101 : une erreur s'est produite lors du démlarrage du serveur Forms....". (in french!)
 
What should i do ?

Thank in advance.
Regards.