diff --git a/.gitignore b/.gitignore
index bf49e5c..b5a1298 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,12 +4,12 @@
 
 # Python directories
 __pycache__
+pve
 
 # CMake build directories
 build*
 
 # Data files and build outputs
-*.gputl
 *.log
 *.metadata
 *.perfetto
diff --git a/lgl_mali_timeline_viewer.py b/lgl_mali_timeline_viewer.py
index bbd98ce..1849b2f 100644
--- a/lgl_mali_timeline_viewer.py
+++ b/lgl_mali_timeline_viewer.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # SPDX-License-Identifier: MIT
 # -----------------------------------------------------------------------------
 # Copyright (c) 2024-2025 Arm Limited
diff --git a/lglpy/android/adb.py b/lglpy/android/adb.py
index a048394..3061237 100644
--- a/lglpy/android/adb.py
+++ b/lglpy/android/adb.py
@@ -29,6 +29,7 @@
 from collections.abc import Iterable
 import os
 import shlex
+import shutil
 import subprocess as sp
 from typing import Optional
 
@@ -64,10 +65,17 @@ def __init__(self, device: Optional[str] = None,
                 None for non-specific use.
             package: The package name, as returned by `adb shell pm list
                 packages` or None for non-specific use.
+
+        Raise:
+            FileNotFoundError will be raised if adb is not available on the
+            environment PATH.
         '''
         self.device = device
         self.package = package
 
+        if not shutil.which('adb'):
+            raise FileNotFoundError('Android adb not found on the PATH')
+
     def set_device(self, device: Optional[str]) -> None:
         '''
         Set the device for this connection.
diff --git a/lglpy/android/perfetto.cfg b/lglpy/android/perfetto.cfg
index a823207..31ffa16 100644
--- a/lglpy/android/perfetto.cfg
+++ b/lglpy/android/perfetto.cfg
@@ -16,12 +16,6 @@ data_sources: {
   producer_name_filter: "{{PACKAGE}}"
 }
 
-data_sources: {
-  config {
-    name: "android.surfaceflinger.frametimeline"
-  }
-}
-
 duration_ms: 60000
 write_into_file: true
 file_write_period_ms: 1000
diff --git a/lglpy/comms/service_gpu_timeline.py b/lglpy/comms/service_gpu_timeline.py
index 20ce567..fad9cd6 100644
--- a/lglpy/comms/service_gpu_timeline.py
+++ b/lglpy/comms/service_gpu_timeline.py
@@ -327,7 +327,10 @@ def handle_header(self, msg: Any) -> None:
             msg: The Python decode of a Timeline PB payload.
         '''
         assert msg.version_no == timeline_pb2.HeaderVersionNo.version_1
-        assert not self.seen_header
+        assert not self.seen_header, (
+            "Handshaking header has already been seen. To start a new "
+            "timeline, you need to restart this script."
+        )
 
         self.seen_header = True
 
diff --git a/lglpy/timeline/gui/timeline/view.py b/lglpy/timeline/gui/timeline/view.py
index 7c94465..077ac4e 100644
--- a/lglpy/timeline/gui/timeline/view.py
+++ b/lglpy/timeline/gui/timeline/view.py
@@ -438,7 +438,7 @@ def load(self, trace_data=None):
                 workload = 'window'
                 style = self.timeline_styles.get_style('Submit', 0, workload)
                 draw = TLSpec.get_box(
-                    'Submit', stime, etime, style, '', '', submit)
+                    'Submit', stime, etime, style, '', '', present)
                 channel.add_object(draw)
 
         # Add scheduling channels
diff --git a/lglpy/timeline/gui/window.py b/lglpy/timeline/gui/window.py
index 6b3c9d2..da149d8 100644
--- a/lglpy/timeline/gui/window.py
+++ b/lglpy/timeline/gui/window.py
@@ -339,7 +339,7 @@ def load_file(self, trace_file, metadata_file=None):
         if not metadata_file:
             postfix = '.perfetto'
             if trace_file.endswith(postfix):
-                metadata_file = f'{trace_file[:-len(postfix)]}.gputl'
+                metadata_file = f'{trace_file[:-len(postfix)]}.metadata'
 
             if not os.path.exists(metadata_file):
                 metadata_file = None