How to change default port number in Dart Editor
You could run pub serve manually pub serve --port 1234 from command line and use a custom launch configuration with a defined URL that points to your pub serve.
dartbug.com is currently not available (at least for me) to verify if there is already a feature request, otherwise you should create one but I think I already saw one a while ago, but I'm not sure.
I'm on OSx platform and I had same error after updating only SDK folder, without updating any other tools, editor ect...
I solved temporarly with launching pub serv manually by terminal
pub serve --port 1234But to solve problem on Eclipse Editor I must clean all files of Dart installation with "AppCleaner" and reinstall all with new installation. With this solution I solved the problem.