Improve configuration for machine identities

[pickfire]

I think it would be nice if the error reporting looks better.

[kaihendry]

I don't quite grok the error... what were you trying to do?

Was it to be expected?

[pickfire]

Maybe make the error inside the <pre> looks like more a real error by any visual aid or seperate it from <pre>. Just a minor improvement in case anyone didn't notice that there is any failure.