About System.Threading.Mutex

Questions & Answers
1

When I open my project use 5.3.5 version, the inside of the original code, tell me the error CS0117: System. Threading. Mutex 'does not contain a definition for OpenExisting’

       ![90745-111.jpg|1100x111](upload://om1S7h6OQkqAkGMA8DDvW7zp3D4.jpeg)Mutex mutex = null;
			try {
				mutex = Mutex.OpenExisting( name );
			} catch( System.Exception ) {
				mutex = null;
			}
2

change api compatibility level to .NET2.0