rasmianu,
Thanks for the additional information, but we need more.
What is your enterprise server and operating system (eg Sun running Solarus 10)?
What is your database server and operating system (eg Sun running Solarus 10)?
What is your database and version (eg Oracle 10g)?
What is your version of JDE EnterpriseOne (eg 8.11 sp1)?
What is your JDE Tools Release (eg 8.97.2.1)?
What is your Web server, operating system and web application server (Intel running Windows Server 2003 and Websphere 6.1)?
What is your Web Development Client (eg WebSphere Express)?
What is the application you are trying to launch (eg P0006)?
Has the application you are trying to launch been modified or is it a custom application?
Have you got a debug log of the attempt to launch the application? If you do, attach it to your post. If you don't - create one and attach it to your post.
What have you done to try to fix it yourself? What happened?
Can you launch a different, standard, unmodified application (eg P0006)?
Please answer ALL the questions above.
My guess is that you do not have a web development client installed on the development fat client. If this is the case, then you will need to install one.