Unmatched Method Signature Gives Unhelpful Exception - Still happens

[tjayharvey]

When a ModifyMethod targets a method that isn't present in the target assembly (possibly because its signature is slightly different) it throws a not very helpful Null Reference Exception that doesn't tell you what method is causing the problem.

[GregRos]

Curse you Tony Hoare!

Admittedly it's a little late, but I'll fix the problem.

[fireundubh]

The KeyNotFoundException message is still not very helpful.

I found that adding this.Logger.Fatal(ex.Message); to the try-catch in ApplyInstructions() actually tells you what's up.