diff --git a/tools/winscope/adb_proxy/winscope_proxy.py b/tools/winscope/adb_proxy/winscope_proxy.py
index 0fba4735b..21a78546e 100755
--- a/tools/winscope/adb_proxy/winscope_proxy.py
+++ b/tools/winscope/adb_proxy/winscope_proxy.py
@@ -235,7 +235,7 @@ class WindowManagerTraceSelectedConfig:
         # defaults set for all configs
         self.selectedConfigs = {
             "wmbuffersize": "16000",
-            "tracinglevel": "all",
+            "tracinglevel": "debug",
             "tracingtype": "frame",
         }
 
diff --git a/tools/winscope/src/DataAdb.vue b/tools/winscope/src/DataAdb.vue
index 85c55ec1e..bd484c8b1 100644
--- a/tools/winscope/src/DataAdb.vue
+++ b/tools/winscope/src/DataAdb.vue
@@ -243,8 +243,8 @@ const WM_SELECTED_CONFIG = {
     'transaction',
   ],
   'tracinglevel': [
-    'all',
-    'trim',
+    'verbose',
+    'debug',
     'critical',
   ],
 };
diff --git a/tools/winscope/src/decode.js b/tools/winscope/src/decode.js
index dde10413f..c4ed60623 100644
--- a/tools/winscope/src/decode.js
+++ b/tools/winscope/src/decode.js
@@ -537,6 +537,7 @@ function decodeAndTransformProto(buffer, params, displayDefaults) {
   // From S onwards, returns a LayerTrace object, iterating over multiple items allows
   // winscope to handle both the new and legacy formats
   // TODO Refactor the decode.js code into a set of decoders to clean up the code
+  let lastError = null;
   for (var x = 0; x < objTypesProto.length; x++) {
     const objType = objTypesProto[x];
     const transform = transforms[x];
@@ -546,9 +547,14 @@ function decodeAndTransformProto(buffer, params, displayDefaults) {
       const transformed = transform(decoded);
       return transformed;
     } catch (e) {
+      lastError = e;
       // check next parser
     }
   }
+
+  if (lastError) {
+    throw lastError;
+  }
   throw new UndetectableFileType('Unable to parse file');
 }
 
diff --git a/tools/winscope/src/flickerlib/WindowManagerState.ts b/tools/winscope/src/flickerlib/WindowManagerState.ts
index 0f132547c..57f3dd7c4 100644
--- a/tools/winscope/src/flickerlib/WindowManagerState.ts
+++ b/tools/winscope/src/flickerlib/WindowManagerState.ts
@@ -89,7 +89,8 @@ function createWindowManagerPolicy(proto: any): WindowManagerPolicy {
 function createRootWindowContainer(proto: any): RootWindowContainer {
     const windowContainer = WindowContainer.fromProto(
         /* proto */ proto.windowContainer,
-        /* childrenProto */ proto.windowContainer.children.reverse()
+        /* childrenProto */ proto.windowContainer?.children?.reverse() ?? [],
+        /* isActivityInTree */ false
     );
 
     if (windowContainer == null) {
diff --git a/tools/winscope/src/flickerlib/windows/Activity.ts b/tools/winscope/src/flickerlib/windows/Activity.ts
index 60e28cdd8..77574b641 100644
--- a/tools/winscope/src/flickerlib/windows/Activity.ts
+++ b/tools/winscope/src/flickerlib/windows/Activity.ts
@@ -25,7 +25,7 @@ Activity.fromProto = function (proto: any): Activity {
     } else {
         const windowContainer = WindowContainer.fromProto(
             /* proto */ proto.windowToken.windowContainer,
-            /* protoChildren */ proto.windowToken.windowContainer.children.reverse(),
+            /* protoChildren */ proto.windowToken.windowContainer?.children?.reverse() ?? [],
             /* isActivityInTree */ true,
             /* nameOverride */ null,
             /* identifierOverride */ proto.identifier
diff --git a/tools/winscope/src/flickerlib/windows/DisplayArea.ts b/tools/winscope/src/flickerlib/windows/DisplayArea.ts
index 0abfdeeaa..a46eaefe4 100644
--- a/tools/winscope/src/flickerlib/windows/DisplayArea.ts
+++ b/tools/winscope/src/flickerlib/windows/DisplayArea.ts
@@ -24,7 +24,7 @@ DisplayArea.fromProto = function (proto: any, isActivityInTree: Boolean): Displa
     } else {
         const windowContainer = WindowContainer.fromProto(
             /* proto */ proto.windowContainer,
-            /* protoChildren */ proto.windowContainer.children.reverse(),
+            /* protoChildren */ proto.windowContainer?.children?.reverse() ?? [],
             /* isActivityInTree */ isActivityInTree,
             /* nameOverride */ proto.name
         );
diff --git a/tools/winscope/src/flickerlib/windows/DisplayContent.ts b/tools/winscope/src/flickerlib/windows/DisplayContent.ts
index 7a9f6af5a..39703ef04 100644
--- a/tools/winscope/src/flickerlib/windows/DisplayContent.ts
+++ b/tools/winscope/src/flickerlib/windows/DisplayContent.ts
@@ -24,7 +24,7 @@ DisplayContent.fromProto = function (proto: any, isActivityInTree: Boolean): Dis
     } else {
         const windowContainer = WindowContainer.fromProto(
             /* proto */ proto.rootDisplayArea.windowContainer,
-            /* protoChildren */ proto.rootDisplayArea.windowContainer.children.reverse(),
+            /* protoChildren */ proto.rootDisplayArea.windowContainer?.children?.reverse() ?? [],
             /* isActivityInTree */ isActivityInTree,
             /* nameOverride */ proto.displayInfo?.name ?? null
         );
diff --git a/tools/winscope/src/flickerlib/windows/Task.ts b/tools/winscope/src/flickerlib/windows/Task.ts
index 685d94173..858360717 100644
--- a/tools/winscope/src/flickerlib/windows/Task.ts
+++ b/tools/winscope/src/flickerlib/windows/Task.ts
@@ -25,7 +25,7 @@ Task.fromProto = function (proto: any, isActivityInTree: Boolean): Task {
         const windowContainerProto = proto.taskFragment?.windowContainer ?? proto.windowContainer;
         const windowContainer = WindowContainer.fromProto(
             /* proto */ windowContainerProto,
-            /* protoChildren */ windowContainerProto.children.reverse(),
+            /* protoChildren */ windowContainerProto?.children?.reverse() ?? [],
             /* isActivityInTree */ isActivityInTree
         );
 
diff --git a/tools/winscope/src/flickerlib/windows/TaskFragment.ts b/tools/winscope/src/flickerlib/windows/TaskFragment.ts
index 8f5eeed99..10f5502b3 100644
--- a/tools/winscope/src/flickerlib/windows/TaskFragment.ts
+++ b/tools/winscope/src/flickerlib/windows/TaskFragment.ts
@@ -24,7 +24,7 @@ TaskFragment.fromProto = function (proto: any, isActivityInTree: Boolean): TaskF
     } else {
         const windowContainer = WindowContainer.fromProto(
             /* proto */ proto.windowContainer,
-            /* protoChildren */ proto.windowContainer.children.reverse(),
+            /* protoChildren */ proto.windowContainer?.children?.reverse() ?? [],
             /* isActivityInTree */ isActivityInTree);
         const entry = new TaskFragment(
             proto.activityType,
diff --git a/tools/winscope/src/flickerlib/windows/WindowContainer.ts b/tools/winscope/src/flickerlib/windows/WindowContainer.ts
index 9a99226d8..7d71f38b2 100644
--- a/tools/winscope/src/flickerlib/windows/WindowContainer.ts
+++ b/tools/winscope/src/flickerlib/windows/WindowContainer.ts
@@ -47,7 +47,8 @@ WindowContainer.fromProto = function (
 
     const children = protoChildren
         .filter(it => it != null)
-        .map(it => WindowContainer.childrenFromProto(it, isActivityInTree));
+        .map(it => WindowContainer.childrenFromProto(it, isActivityInTree))
+        .filter(it => it != null);
 
     const identifier = identifierOverride ?? proto.identifier;
     var name = nameOverride ?? identifier?.title ?? "";
diff --git a/tools/winscope/src/flickerlib/windows/WindowState.ts b/tools/winscope/src/flickerlib/windows/WindowState.ts
index 0b79d7306..a9cdf0829 100644
--- a/tools/winscope/src/flickerlib/windows/WindowState.ts
+++ b/tools/winscope/src/flickerlib/windows/WindowState.ts
@@ -29,7 +29,7 @@ import WindowContainer from "./WindowContainer"
         const name = getName(identifierName);
         const windowContainer = WindowContainer.fromProto(
             /* proto */ proto.windowContainer,
-            /* protoChildren */ proto.windowContainer.children.reverse(),
+            /* protoChildren */ proto.windowContainer?.children.reverse() ?? [],
             /* isActivityInTree */ isActivityInTree,
             /* nameOverride */ name,
             /* identifierOverride */ proto.identifier
diff --git a/tools/winscope/src/flickerlib/windows/WindowToken.ts b/tools/winscope/src/flickerlib/windows/WindowToken.ts
index 3187dd06e..ca973237d 100644
--- a/tools/winscope/src/flickerlib/windows/WindowToken.ts
+++ b/tools/winscope/src/flickerlib/windows/WindowToken.ts
@@ -25,7 +25,7 @@ WindowToken.fromProto = function (proto: any, isActivityInTree: Boolean): Window
 
     const windowContainer = WindowContainer.fromProto(
         /* proto */ proto.windowContainer,
-        /* protoChildren */ proto.windowContainer.children.reverse(),
+        /* protoChildren */ proto.windowContainer?.children?.reverse() ?? [],
         /* isActivityInTree */ isActivityInTree,
         /* nameOverride */ null,
         /* identifierOverride */ null,