What does the question mark in member access mean in C#?

Question

Can someone please explain to me what does the question mark in the member access in the following code means?

Is it part of standard C#? I get parse errors when try

Answer 1

In C# version 6 it will be shorthand for

if (this.AnalyzerLoadFailed != null)
    this.AnalyzerLoadFailed.Invoke(this, new AnalyzerLoadFailureEventArgs(AnalyzerLoadFailureEventArgs.FailureErrorCode.NoAnalyzers, null, null));