问题
I am getting an occasional 'XMLHttpRequest cannot load' error while using the cloud 9 cloud hosted development environment.
The full error is 'XMLHttpRequest cannot load https://c9.io/_user_content/authorize?redirect=http%3A%2F%2FprojName-username.c9.io%2Fusers%2Fanswers. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://projName-username.c9.io' is therefore not allowed access.'
The error is inconsistent. It has shown up (and not shown up) on various pages and often my page will work if I just reload it and try the exact same thing again. Is anyone else running into this error on cloud 9 or perhaps my internet connection is just unreliable? I am using the MEAN stack on a micro instance of cloud 9 with 1 GB ram and 10GB storage.
回答1:
This is a temporary bug that arose as a result of changing the app preview URL from c9.io to c9users.io. The change was made in order to protect users and increase security. A fix will be out for this soon.
In the meantime you can set your application to public (your code will still be private and undiscoverable) by clicking "Share" in the top right and then checking the box next to your application URL.
Update: This bug has now been fixed. Any further issues similar to this should be submitted at https://community.c9.io so they can be addressed properly.
来源：https://stackoverflow.com/questions/33441369/xmlhttprequest-cannot-load-cloud-9-io