diff --git a/examples/DemoRunner/JuceLibraryCode/AppConfig.h b/examples/DemoRunner/JuceLibraryCode/AppConfig.h
index 7c6bfaa70f..26f07d22d9 100644
--- a/examples/DemoRunner/JuceLibraryCode/AppConfig.h
+++ b/examples/DemoRunner/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_analytics              1
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics           1
diff --git a/examples/DemoRunner/JuceLibraryCode/JuceHeader.h b/examples/DemoRunner/JuceLibraryCode/JuceHeader.h
index 06f7f81401..1cc5e7acf5 100644
--- a/examples/DemoRunner/JuceLibraryCode/JuceHeader.h
+++ b/examples/DemoRunner/JuceLibraryCode/JuceHeader.h
@@ -36,6 +36,15 @@
 #include <juce_video/juce_video.h>
 
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/AudioPerformanceTest/JuceLibraryCode/AppConfig.h b/extras/AudioPerformanceTest/JuceLibraryCode/AppConfig.h
index 954761b210..f960245707 100644
--- a/extras/AudioPerformanceTest/JuceLibraryCode/AppConfig.h
+++ b/extras/AudioPerformanceTest/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics          1
 #define JUCE_MODULE_AVAILABLE_juce_audio_devices         1
diff --git a/extras/AudioPerformanceTest/JuceLibraryCode/JuceHeader.h b/extras/AudioPerformanceTest/JuceLibraryCode/JuceHeader.h
index 82feea7ca6..1368bac8be 100644
--- a/extras/AudioPerformanceTest/JuceLibraryCode/JuceHeader.h
+++ b/extras/AudioPerformanceTest/JuceLibraryCode/JuceHeader.h
@@ -27,6 +27,15 @@
 #include <juce_gui_extra/juce_gui_extra.h>
 
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/AudioPluginHost/JuceLibraryCode/AppConfig.h b/extras/AudioPluginHost/JuceLibraryCode/AppConfig.h
index f2c41a734b..fe67b2425f 100644
--- a/extras/AudioPluginHost/JuceLibraryCode/AppConfig.h
+++ b/extras/AudioPluginHost/JuceLibraryCode/AppConfig.h
@@ -49,6 +49,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics          1
 #define JUCE_MODULE_AVAILABLE_juce_audio_devices         1
diff --git a/extras/AudioPluginHost/JuceLibraryCode/JuceHeader.h b/extras/AudioPluginHost/JuceLibraryCode/JuceHeader.h
index 01d36b3b84..5b63c7a0c8 100644
--- a/extras/AudioPluginHost/JuceLibraryCode/JuceHeader.h
+++ b/extras/AudioPluginHost/JuceLibraryCode/JuceHeader.h
@@ -31,6 +31,15 @@
 
 #include "BinaryData.h"
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/BinaryBuilder/JuceLibraryCode/AppConfig.h b/extras/BinaryBuilder/JuceLibraryCode/AppConfig.h
index 163583165c..9379095972 100644
--- a/extras/BinaryBuilder/JuceLibraryCode/AppConfig.h
+++ b/extras/BinaryBuilder/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_core      1
 
diff --git a/extras/BinaryBuilder/JuceLibraryCode/JuceHeader.h b/extras/BinaryBuilder/JuceLibraryCode/JuceHeader.h
index ce4d6d90cc..990925e65a 100644
--- a/extras/BinaryBuilder/JuceLibraryCode/JuceHeader.h
+++ b/extras/BinaryBuilder/JuceLibraryCode/JuceHeader.h
@@ -17,6 +17,15 @@
 #include <juce_core/juce_core.h>
 
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/NetworkGraphicsDemo/JuceLibraryCode/AppConfig.h b/extras/NetworkGraphicsDemo/JuceLibraryCode/AppConfig.h
index 22f64728ca..c26ad9b2d1 100644
--- a/extras/NetworkGraphicsDemo/JuceLibraryCode/AppConfig.h
+++ b/extras/NetworkGraphicsDemo/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics          1
 #define JUCE_MODULE_AVAILABLE_juce_audio_devices         1
diff --git a/extras/NetworkGraphicsDemo/JuceLibraryCode/JuceHeader.h b/extras/NetworkGraphicsDemo/JuceLibraryCode/JuceHeader.h
index b72437d24d..e7443e5872 100644
--- a/extras/NetworkGraphicsDemo/JuceLibraryCode/JuceHeader.h
+++ b/extras/NetworkGraphicsDemo/JuceLibraryCode/JuceHeader.h
@@ -31,6 +31,15 @@
 
 #include "BinaryData.h"
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/Projucer/JuceLibraryCode/AppConfig.h b/extras/Projucer/JuceLibraryCode/AppConfig.h
index 3620ea1535..0e658d0158 100644
--- a/extras/Projucer/JuceLibraryCode/AppConfig.h
+++ b/extras/Projucer/JuceLibraryCode/AppConfig.h
@@ -66,6 +66,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_analytics            1
 #define JUCE_MODULE_AVAILABLE_juce_core                 1
diff --git a/extras/Projucer/JuceLibraryCode/JuceHeader.h b/extras/Projucer/JuceLibraryCode/JuceHeader.h
index f3f49db042..83d8f2395b 100644
--- a/extras/Projucer/JuceLibraryCode/JuceHeader.h
+++ b/extras/Projucer/JuceLibraryCode/JuceHeader.h
@@ -25,6 +25,15 @@
 
 #include "BinaryData.h"
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/UnitTestRunner/JuceLibraryCode/AppConfig.h b/extras/UnitTestRunner/JuceLibraryCode/AppConfig.h
index 2257f53557..5fdd6364e4 100644
--- a/extras/UnitTestRunner/JuceLibraryCode/AppConfig.h
+++ b/extras/UnitTestRunner/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_analytics              1
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics           1
diff --git a/extras/UnitTestRunner/JuceLibraryCode/JuceHeader.h b/extras/UnitTestRunner/JuceLibraryCode/JuceHeader.h
index b4cfd548cb..1b016ebae4 100644
--- a/extras/UnitTestRunner/JuceLibraryCode/JuceHeader.h
+++ b/extras/UnitTestRunner/JuceLibraryCode/JuceHeader.h
@@ -35,6 +35,15 @@
 #include <juce_video/juce_video.h>
 
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
diff --git a/extras/WindowsDLL/JuceLibraryCode/AppConfig.h b/extras/WindowsDLL/JuceLibraryCode/AppConfig.h
index ab2260832c..aee356abe8 100644
--- a/extras/WindowsDLL/JuceLibraryCode/AppConfig.h
+++ b/extras/WindowsDLL/JuceLibraryCode/AppConfig.h
@@ -47,6 +47,8 @@
 
 #define JUCE_USE_DARK_SPLASH_SCREEN 1
 
+#define JUCE_PROJUCER_VERSION 0x50404
+
 //==============================================================================
 #define JUCE_MODULE_AVAILABLE_juce_audio_basics          1
 #define JUCE_MODULE_AVAILABLE_juce_audio_devices         1
diff --git a/extras/WindowsDLL/JuceLibraryCode/JuceHeader.h b/extras/WindowsDLL/JuceLibraryCode/JuceHeader.h
index c7101cce7d..91fef65b93 100644
--- a/extras/WindowsDLL/JuceLibraryCode/JuceHeader.h
+++ b/extras/WindowsDLL/JuceLibraryCode/JuceHeader.h
@@ -30,6 +30,15 @@
 #include <juce_video/juce_video.h>
 
 
+#if defined (JUCE_PROJUCER_VERSION) && JUCE_PROJUCER_VERSION < JUCE_VERSION
+ /** If you've hit this error then the version of the Projucer that was used to generate this project is
+     older than the version of the JUCE modules being included. To fix this error, re-save your project
+     using the latest version of the Projucer or, if you aren't using the Projucer to manage your project,
+     remove the JUCE_PROJUCER_VERSION define from the AppConfig.h file.
+ */
+ #error "This project was last saved using an outdated version of the Projucer! Re-save this project with the latest version to fix this error."
+#endif
+
 #if ! DONT_SET_USING_JUCE_NAMESPACE
  // If your code uses a lot of JUCE classes, then this will obviously save you
  // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.