Problems with Designer, when using Port 80

When changing to port 80, I am able to see the project fine on the browser.

But when I log on with Designer, it doesn’t play so well.

First of, discovery of Projects/Designers, in Design Launcher doesn’t work.
I can however successfully add the address manually, using port 80.

After this I can load up the Project.
But I can not edit any views, new as well as old ones.
When I open a view, it hangs on “initializing”

I’ve searched this forum up and down, for this fault, but have not been able to find a solution.
I’ve tested the designer on the local machine, which is serving the project, and everything works fine there. Both the designer and serving of the pages.

The problem only shows, when using a Remote Designer.

If I change the project back to port 8088, it works just as it’s supposed to.

NB:
Steps I’ve taken before this error occurred:

  1. Changed the computer name to a userfriendly name
  2. Changed the port number to 80

Summerize:
Designing views does not work on port 80, on a remote machine.

All help highly appreciated.

Thanks, V

Turned out to be a corporate network problem.