Don't crash if assembly resolution fails.

ICSharpCode.Decompiler.Console/CustomAssemblyResolver.cs

@@ -52,6 +52,7 @@ namespace ICSharpCode.Decompiler.Console
 
 		public override AssemblyDefinition Resolve(AssemblyNameReference name, ReaderParameters parameters)
 		{
+			try {
 				var targetFramework = TargetFramework.Split(new[] { ",Version=v" }, StringSplitOptions.None);
 				string file = null;
 				switch (targetFramework[0]) {
@@ -77,6 +78,10 @@ namespace ICSharpCode.Decompiler.Console
 					default:
 						return base.Resolve(name, parameters);
 				}
+			} catch (AssemblyResolutionException exception) {
+				System.Console.WriteLine(exception.ToString());
+				return null;
+			}
 		}
 	}
 }