We modified the domain for which our code is from http://www.ourdomain.com/to app.ourdomain.com. Moved and update all the fields I could find with the domain in which Facebook developers, including the URL of a site, domain, site, URL, secure fabric canvas URL.
When you try to access our Facebook application, you receive an error response is empty. To pinpoint the problem, I created a file named test .html and put a library-only one line of code, Hello world. You can get the same error when trying to access the same file by switching: apps.facebook.com/myapp/test.html, when I load the URL canvas directly (app.ourdomain.com/test.html) is loading properly.
Any ideas or suggestions on what can further be solved? Facebook does not allow you to change these areas after they formed?