System properties specified as environment variables throw unhelpful ArgumentException

[NightOwl888]

System properties are supposed to be prefixed with lucene: when using environment variables. And when you do, it works.

However, if you forget and specify them like you would in a configuration file or NUnit property, incorrectly using something like tests:crashmode instead of lucene:tests:crashmode, it throws the exception:

System.ArgumentException : Value does not fall within the expected range.

Clearly, this message doesn't lead you to the correct solution. This message should be fixed to clearly spell out that the "lucene:" prefix is missing.