diff --git a/src/lib.rs b/src/lib.rs
index bd3c724..cafa7b7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -362,19 +362,19 @@ impl MessageBehavior for VmcExtBlendVal {
             ],
         };
     }
-    fn from_osc_message(msg: OscMessage) -> Result<Self, String> {
+    fn from_osc_message(msg: OscMessage) -> Result<Self, FromMessageErr> {
         let name: String;
         let value: f32;
         if msg.args.len() != 2 {
-            return Err(String::from("arg count invalid"));
+            return Err(FromMessageErr::ArgCount(ArgCountErr { expected_in: vec![2], actual: msg.args.len(), addr: msg.addr}));
         }
         match &msg.args[0] {
             OscType::String(s) => name = s.to_owned(),
-            _ => return Err(String::from("arg type invalid")),
+            _ => return Err(FromMessageErr::ArgType(ArgTypeErr { expected: OscType::String(String::new()), actual: msg.args[0], addr: msg.addr, arg_count: 0})),
         }
         match msg.args[1] {
             OscType::Float(f) => value = f,
-            _ => return Err(String::from("arg type invalid")),
+            _ => return Err(FromMessageErr::ArgType(ArgTypeErr { expected: OscType::Float(0.0), actual: msg.args[1], addr: msg.addr, arg_count: 1})),
         }
         return Ok(VmcExtBlendVal { name, value });
     }