Debugging Apache Bad Request
I got the following error this morning:
Your browser sent a request that this server could not understand.
Additionally, a 400 Bad Request error was encountered while trying to use an ErrorDocument to handle the request.
I didn't see anything in the Apache log file, so I increased the
LogLevel debug. Turns out I was using an underscore (_) in my URL!
AH02415: [strict] Invalid host name 'some_test.dev', problem near: _test.
AH00550: Client sent malformed Host header: some_test.dev