If you are currently experiencing issues when submitting a case to BC please reach out to our chat support or private message me with the following details below so we can investigate further.
Exact steps to replicate the issue. e.g. TS or CS case? Attachment?
At exactly which step produced the error? e.g. Which button was clicked?
The exact error message? e.g. There are 2 different types of 404 pages. Capturing the URL and screenshot would help.
If experiencing a 404, try hit the following url and capture the details - http://www.adobe.com/cfusion/build_data.cfm This will help us to hone in on the application server that caused the error so that we can look into the logs on that server.
What happens when you get the 404? Is the case submission lost and you have to resubmit?