diff --git a/integrations/actix/src/lib.rs b/integrations/actix/src/lib.rs
index 0c311d223..879d920be 100644
--- a/integrations/actix/src/lib.rs
+++ b/integrations/actix/src/lib.rs
@@ -292,7 +292,12 @@ pub fn handle_server_fns_with_context(
                 } else {
                     HttpResponse::BadRequest().body(format!(
                         "Could not find a server function at the route {:?}. \
-                         \n\nIt's likely that you need to call \
+                         \n\nIt's likely that either 
+                         1. The API prefix you specify in the `#[server]` \
+                         macro doesn't match the prefix at which your server \
+                         function handler is mounted, or \n2. You are on a \
+                         platform that doesn't support automatic server \
+                         function registration and you need to call \
                          ServerFn::register_explicit() on the server function \
                          type, somewhere in your `main` function.",
                         req.path()
diff --git a/integrations/axum/src/lib.rs b/integrations/axum/src/lib.rs
index 8cc9cebd7..716c35bb5 100644
--- a/integrations/axum/src/lib.rs
+++ b/integrations/axum/src/lib.rs
@@ -335,9 +335,14 @@ async fn handle_server_fns_inner(
                 Response::builder().status(StatusCode::BAD_REQUEST).body(
                     Full::from(format!(
                         "Could not find a server function at the route \
-                         {fn_name}. \n\nIt's likely that you need to call \
+                         {fn_name}. \n\nIt's likely that either 
+                         1. The API prefix you specify in the `#[server]` \
+                         macro doesn't match the prefix at which your server \
+                         function handler is mounted, or \n2. You are on a \
+                         platform that doesn't support automatic server \
+                         function registration and you need to call \
                          ServerFn::register_explicit() on the server function \
-                         type, somewhere in your `main` function."
+                         type, somewhere in your `main` function.",
                     )),
                 )
             }
diff --git a/integrations/viz/src/lib.rs b/integrations/viz/src/lib.rs
index 13eb24f52..9de53a0f5 100644
--- a/integrations/viz/src/lib.rs
+++ b/integrations/viz/src/lib.rs
@@ -312,10 +312,17 @@ async fn handle_server_fns_inner(
                                 .body(Body::from(format!(
                                     "Could not find a server function at the \
                                      route {fn_name}. \n\nIt's likely that \
-                                     you need to call \
+                                     either 
+                                    1. The API prefix you specify in the \
+                                     `#[server]` macro doesn't match the \
+                                     prefix at which your server function \
+                                     handler is mounted, or \n2. You are on a \
+                                     platform that doesn't support automatic \
+                                     server function registration and you \
+                                     need to call \
                                      ServerFn::register_explicit() on the \
                                      server function type, somewhere in your \
-                                     `main` function."
+                                     `main` function.",
                                 )))
                         }
                         .expect("could not build Response");
diff --git a/server_fn/src/lib.rs b/server_fn/src/lib.rs
index 35752c792..0d9831c18 100644
--- a/server_fn/src/lib.rs
+++ b/server_fn/src/lib.rs
@@ -608,6 +608,12 @@ where
         #[cfg(not(target_arch = "wasm32"))]
         let binary = binary.as_ref();
 
+        if status == 400 {
+            return Err(ServerFnError::ServerError(
+                "No server function was found at this URL.".to_string(),
+            ));
+        }
+
         ciborium::de::from_reader(binary)
             .map_err(|e| ServerFnError::Deserialization(e.to_string()))
     } else {
@@ -616,6 +622,10 @@ where
             .await
             .map_err(|e| ServerFnError::Deserialization(e.to_string()))?;
 
+        if status == 400 {
+            return Err(ServerFnError::ServerError(text));
+        }
+
         let mut deserializer = JSONDeserializer::from_str(&text);
         T::deserialize(&mut deserializer)
             .map_err(|e| ServerFnError::Deserialization(e.to_string()))