diff --git a/crates/viewer/re_global_context/src/app_options.rs b/crates/viewer/re_global_context/src/app_options.rs
index 29c3ee864baf..66c17f714714 100644
--- a/crates/viewer/re_global_context/src/app_options.rs
+++ b/crates/viewer/re_global_context/src/app_options.rs
@@ -8,29 +8,37 @@ const MAPBOX_ACCESS_TOKEN_ENV_VAR: &str = "RERUN_MAPBOX_ACCESS_TOKEN";
 #[serde(default)]
 pub struct AppOptions {
     /// Warn if the e2e latency exceeds this value.
+    #[serde(default)]
     pub warn_e2e_latency: f32,
 
     /// Show milliseconds, RAM usage, etc.
+    #[serde(default)]
     pub show_metrics: bool,
 
     /// Include the "Welcome screen" application in the recordings panel?
     #[serde(alias = "include_welcome_screen_button_in_recordings_panel")]
+    #[serde(default)]
     pub include_rerun_examples_button_in_recordings_panel: bool,
 
     /// Displays an overlay for debugging picking.
+    #[serde(default)]
     pub show_picking_debug_overlay: bool,
 
     /// Inspect the blueprint timeline.
+    #[serde(default)]
     pub inspect_blueprint_timeline: bool,
 
     /// Disable garbage collection of the blueprint.
+    #[serde(default)]
     pub blueprint_gc: bool,
 
     /// What time zone to display timestamps in.
     #[serde(rename = "timestamp_format")]
+    #[serde(default)]
     pub timestamp_format: TimestampFormat,
 
     /// Preferred method for video decoding on web.
+    #[serde(default)]
     pub video_decoder_hw_acceleration: DecodeHardwareAcceleration,
 
     /// Override the path to the FFmpeg binary.
@@ -41,17 +49,20 @@ pub struct AppOptions {
     /// Implementation note: we avoid using `Option<PathBuf>` here to avoid losing the user-defined
     /// path when disabling the override.
     #[allow(clippy::doc_markdown)]
+    #[serde(default)]
     pub video_decoder_override_ffmpeg_path: bool,
 
     /// Custom path to the FFmpeg binary.
     ///
     /// Don't use this field directly, use [`AppOptions::video_decoder_settings`] instead.
     #[allow(clippy::doc_markdown)]
+    #[serde(default)]
     pub video_decoder_ffmpeg_path: String,
 
     /// Mapbox API key (used to enable Mapbox-based map view backgrounds).
     ///
     /// Can also be set using the `RERUN_MAPBOX_ACCESS_TOKEN` environment variable.
+    #[serde(default)]
     pub mapbox_access_token: String,
 
     /// Path to the directory suitable for storing cache data.
@@ -62,6 +73,7 @@ pub struct AppOptions {
     /// *NOTE*: subsystems making use of the cache directory should use a unique sub-directory name,
     /// see [`AppOptions::cache_subdirectory`].
     #[cfg(not(target_arch = "wasm32"))]
+    #[serde(default)]
     pub cache_directory: Option<std::path::PathBuf>,
 }
 
diff --git a/crates/viewer/re_time_panel/src/time_panel.rs b/crates/viewer/re_time_panel/src/time_panel.rs
index f276645b3d8a..cdd95734b961 100644
--- a/crates/viewer/re_time_panel/src/time_panel.rs
+++ b/crates/viewer/re_time_panel/src/time_panel.rs
@@ -97,9 +97,11 @@ impl From<TimePanelSource> for re_log_types::StoreKind {
 #[derive(serde::Deserialize, serde::Serialize)]
 #[serde(default)]
 pub struct TimePanel {
+    #[serde(skip)]
     data_density_graph_painter: data_density_graph::DataDensityGraphPainter,
 
     /// Width of the entity name columns previous frame.
+    #[serde(skip)]
     prev_col_width: f32,
 
     /// The right side of the entity name column; updated during its painting.
@@ -111,6 +113,7 @@ pub struct TimePanel {
     time_ranges_ui: TimeRangesUi,
 
     /// Ui elements for controlling time.
+    #[serde(skip)]
     time_control_ui: TimeControlUi,
 
     /// Which source is the time panel controlling?
@@ -138,6 +141,7 @@ pub struct TimePanel {
     ///
     /// IMPORTANT: Always make sure that the item will be drawn this or next frame when setting this
     /// to `Some`, so that this flag is immediately consumed.
+    #[serde(skip)]
     scroll_to_me_item: Option<Item>,
 
     /// If the timestamp is being edited, the current value.
diff --git a/crates/viewer/re_viewer/src/app_state.rs b/crates/viewer/re_viewer/src/app_state.rs
index c9e94031fd89..c8cf1f725e5a 100644
--- a/crates/viewer/re_viewer/src/app_state.rs
+++ b/crates/viewer/re_viewer/src/app_state.rs
@@ -34,19 +34,29 @@ const WATERMARK: bool = false; // Nice for recording media material
 #[serde(default)]
 pub struct AppState {
     /// Global options for the whole viewer.
+    #[serde(default)]
     pub(crate) app_options: AppOptions,
 
     /// Configuration for the current recording (found in [`EntityDb`]).
+    #[serde(default)]
     pub recording_configs: HashMap<StoreId, RecordingConfig>,
+
+    #[serde(default)]
     pub blueprint_cfg: RecordingConfig,
 
     /// Maps blueprint id to the current undo state for it.
     #[serde(skip)]
     pub blueprint_undo_state: HashMap<StoreId, BlueprintUndoState>,
 
+    #[serde(default)]
     selection_panel: re_selection_panel::SelectionPanel,
+
+    #[serde(default)]
     time_panel: re_time_panel::TimePanel,
+
+    #[serde(default)]
     blueprint_time_panel: re_time_panel::TimePanel,
+
     #[serde(skip)]
     blueprint_tree: re_blueprint_tree::BlueprintTree,
 
@@ -57,6 +67,7 @@ pub struct AppState {
     datastore_ui: re_chunk_store_ui::DatastoreUi,
 
     /// Redap server catalogs and browser UI
+    #[serde(default)]
     pub(crate) redap_servers: RedapServers,
 
     #[serde(skip)]