diff --git a/crates/sylpheed-viewer/src/iso_loader.rs b/crates/sylpheed-viewer/src/iso_loader.rs
index d6463ae..b420e28 100644
--- a/crates/sylpheed-viewer/src/iso_loader.rs
+++ b/crates/sylpheed-viewer/src/iso_loader.rs
@@ -786,6 +786,11 @@ pub struct SaveBrowser {
     pub result: Option<Box<SaveResult>>,
     /// Show the fields that are still unidentified.
     pub show_unknown: bool,
+    /// Set by the window's own "Open savedata…" button. It cannot send
+    /// [`RequestSaveOpen`] itself: a system may not hold an `EventWriter` and an
+    /// `EventReader` for the same event type, and `draw_save_ui` already reads
+    /// this one (Bevy B0002).
+    pub request_open: bool,
 }
 
 /// Ask the loader to open + parse a `savedata` file. `None` = show a file
@@ -4267,7 +4272,14 @@ fn handle_save_open_request(
     channels: Res<IsoChannels>,
     mut saves: ResMut<SaveBrowser>,
 ) {
-    let Some(req) = events.read().last() else {
+    // Either the View-menu event, or the in-window button's flag.
+    let want = match events.read().last() {
+        Some(req) => Some(req.path.clone()),
+        None if saves.request_open => Some(None),
+        None => None,
+    };
+    saves.request_open = false;
+    let Some(want) = want else {
         return;
     };
     if saves.loading {
@@ -4275,7 +4287,6 @@ fn handle_save_open_request(
     }
     saves.loading = true;
     saves.open = true;
-    let want = req.path.clone();
     let sender = channels.sender.clone();
     std::thread::spawn(move || {
         let path = match want {
diff --git a/crates/sylpheed-viewer/src/ui.rs b/crates/sylpheed-viewer/src/ui.rs
index d1045c2..d31a4e1 100644
--- a/crates/sylpheed-viewer/src/ui.rs
+++ b/crates/sylpheed-viewer/src/ui.rs
@@ -2122,7 +2122,6 @@ fn draw_save_ui(
     mut contexts: EguiContexts,
     mut saves: ResMut<SaveBrowser>,
     mut requests: EventReader<RequestSaveOpen>,
-    mut open_save: EventWriter<RequestSaveOpen>,
 ) {
     if requests.read().next().is_some() {
         saves.open = true;
@@ -2289,8 +2288,10 @@ fn draw_save_ui(
             });
         });
 
+    // A flag, not a self-send: holding both an EventReader and an EventWriter
+    // for RequestSaveOpen in one system is a Bevy B0002 panic at startup.
     if reopen {
-        open_save.send(RequestSaveOpen::default());
+        saves.request_open = true;
     }
     saves.open &= open;
 }