Formeditor not running in Developer 8.0.0. b3

Classic Servoy
1

After import the 7.x-Solution into 8.0.0. b3 ,
and try to Open a Form in Editor (CTRL-A),
it get at position in the developer, were it should be the formeditor, this :

HTTP Status 404 - /rfb/angular/index.html
[attachment=0]Screen Shot 07-29-15 at 01.04 PM.JPG[/attachment]
Thank you for any help.

Screen Shot 07-29-15 at 01.04 PM.JPG
Screen Shot 07-29-15 at 01.04 PM.JPG1937×1097 183 KB

2

OK, I found the Issue.
The Developer was on a used Port.

I Changed it in …pathToDeveloper\application_server\server\conf\server.xml