diff --git a/docs/Makefile b/docs/Makefile
index 9296811e02..ae495eb36d 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -2,7 +2,8 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+# SPHINXOPTS with -W means turn warnings into errors to fail the build when warnings are present.
+SPHINXOPTS    = -W
 SPHINXBUILD   = sphinx-build
 SPHINXPROJ    = PythonRobotics
 SOURCEDIR     = .
diff --git a/docs/modules/0_getting_started/3_how_to_contribute_main.rst b/docs/modules/0_getting_started/3_how_to_contribute_main.rst
index 874564cbb8..1e61760649 100644
--- a/docs/modules/0_getting_started/3_how_to_contribute_main.rst
+++ b/docs/modules/0_getting_started/3_how_to_contribute_main.rst
@@ -187,6 +187,7 @@ If you would like to support us in some other way, please contact with creating
 
 Current Major Sponsors:
 
+#. `GitHub`_ : They are providing a GitHub Copilot Pro license for this OSS development.
 #. `JetBrains`_ : They are providing a free license of their IDEs for this OSS development.
 #. `1Password`_ : They are providing a free license of their 1Password team license for this OSS project.
 
@@ -202,6 +203,7 @@ Current Major Sponsors:
 .. _`doc README`: https://github.com/AtsushiSakai/PythonRobotics/blob/master/docs/README.md
 .. _`test_codestyle.py`: https://github.com/AtsushiSakai/PythonRobotics/blob/master/tests/test_codestyle.py
 .. _`JetBrains`: https://www.jetbrains.com/
+.. _`GitHub`: https://www.github.com/
 .. _`Sponsor @AtsushiSakai on GitHub Sponsors`: https://github.com/sponsors/AtsushiSakai
 .. _`Become a backer or sponsor on Patreon`: https://www.patreon.com/myenigma
 .. _`One-time donation via PayPal`: https://www.paypal.com/paypalme/myenigmapay/
diff --git a/docs/modules/1_introduction/1_definition_of_robotics/definition_of_robotics_main.rst b/docs/modules/1_introduction/1_definition_of_robotics/definition_of_robotics_main.rst
index 5d78bf858b..ca595301a6 100644
--- a/docs/modules/1_introduction/1_definition_of_robotics/definition_of_robotics_main.rst
+++ b/docs/modules/1_introduction/1_definition_of_robotics/definition_of_robotics_main.rst
@@ -104,4 +104,4 @@ Robotics consists of several essential components:
 #. Software & Algorithms – Allow the robot to function and make intelligent decisions (e.g., ROS, Machine learning models, Localization, Mapping, Path planning, Control).
 
 This project, `PythonRobotics`, focuses on the software and algorithms part of robotics.
-If you are interested in `Sensors` hardware, you can check :ref:`Internal Sensors for Robotics`_ or :ref:`External Sensors for Robotics`_.
+If you are interested in `Sensors` hardware, you can check :ref:`Internal Sensors for Robots` or :ref:`External Sensors for Robots`.
diff --git a/docs/modules/4_slam/graph_slam/graphSLAM_SE2_example.rst b/docs/modules/4_slam/graph_slam/graphSLAM_SE2_example.rst
index 491320512b..15963aff79 100644
--- a/docs/modules/4_slam/graph_slam/graphSLAM_SE2_example.rst
+++ b/docs/modules/4_slam/graph_slam/graphSLAM_SE2_example.rst
@@ -165,7 +165,7 @@ different data sources into a single optimization problem.
             6             215.8405          -0.000000
 
 
-.. figure:: graphSLAM_SE2_example_files/Graph_SLAM_optimization.gif
+.. image:: https://github.com/AtsushiSakai/PythonRoboticsGifs/raw/master/SLAM/GraphBasedSLAM/Graph_SLAM_optimization.gif
 
 .. code:: ipython3