diff --git a/core/startos/src/install/mod.rs b/core/startos/src/install/mod.rs
index bb7d1a02e..707503615 100644
--- a/core/startos/src/install/mod.rs
+++ b/core/startos/src/install/mod.rs
@@ -198,12 +198,22 @@ pub async fn sideload(ctx: RpcContext) -> Result<SideloadResponse, Error> {
                 use axum::extract::ws::Message;
                 async move {
                     if let Err(e) = async {
-                        let id = id_recv.await.map_err(|_| {
+                        let id = match id_recv.await.map_err(|_| {
                             Error::new(
                                 eyre!("Could not get id to watch progress"),
                                 ErrorKind::Cancelled,
                             )
-                        })?;
+                        }).and_then(|a|a) {
+                            Ok(a) => a,
+                            Err(e) =>{ ws.send(Message::Text(
+                                serde_json::to_string(&Err::<(), _>(RpcError::from(e.clone_output())))
+                                .with_kind(ErrorKind::Serialization)?,
+                            ))
+                            .await
+                            .with_kind(ErrorKind::Network)?;
+                            return Err(e);
+                        }
+                        };
                         tokio::select! {
                             res = async {
                                 while let Some(_) = sub.recv().await {
@@ -259,17 +269,25 @@ pub async fn sideload(ctx: RpcContext) -> Result<SideloadResponse, Error> {
     .await;
     tokio::spawn(async move {
         if let Err(e) = async {
-            let s9pk = S9pk::deserialize(
+            match S9pk::deserialize(
                 &file, None, // TODO
             )
-            .await?;
-            let _ = id_send.send(s9pk.as_manifest().id.clone());
-            ctx.services
-                .install(ctx.clone(), s9pk, None::<Never>)
-                .await?
-                .await?
-                .await?;
-            file.delete().await
+            .await
+            {
+                Ok(s9pk) => {
+                    let _ = id_send.send(Ok(s9pk.as_manifest().id.clone()));
+                    ctx.services
+                        .install(ctx.clone(), s9pk, None::<Never>)
+                        .await?
+                        .await?
+                        .await?;
+                    file.delete().await
+                }
+                Err(e) => {
+                    let _ = id_send.send(Err(e.clone_output()));
+                    return Err(e);
+                }
+            }
         }
         .await
         {
diff --git a/core/startos/src/s9pk/v2/compat.rs b/core/startos/src/s9pk/v2/compat.rs
index 835c86b87..ec5b586ea 100644
--- a/core/startos/src/s9pk/v2/compat.rs
+++ b/core/startos/src/s9pk/v2/compat.rs
@@ -209,7 +209,9 @@ impl S9pk<Section<MultiCursorFile>> {
                 .invoke(ErrorKind::Filesystem)
                 .await?;
             archive.insert_path(
-                Path::new("assets").join(&asset_id),
+                Path::new("assets")
+                    .join(&asset_id)
+                    .with_extension("squashfs"),
                 Entry::file(PackSource::File(sqfs_path)),
             )?;
         }