When ever you get some error. Which document you will prefer?
1. FAQ
2. Troubleshooting Document

If it is printer, then second.
if something else, then google.

FAQ is usually information about feature tricks for me.

I prefer error messages that actually say what the problem is.

1) actually documentation with error codes in it

2) troubleshooting doc

3) go find the dev responsible

^^ in that order.

these are two very different sources of info. And each has its own use cases.

In your given case I'd be looking for either troubleshooting docs (that'd be one hell of a job to write it properly!!!) or docs in general - I'd like to see how different is my setup than what it should be according to docs.

Giving developer a FAQ in these occasions is just a spit into face.

I prefer stack trace, if it’s not possible than error codes that don’t duplicate.

If it is code, then obviously tracelog of the error, then googling around.

You should clarify which product you have. Different products usually have different best ways to debug their errors