README: add note for incompatible MSYS2 Qt version

README.md

@@ -204,6 +204,12 @@ The Monero GUI on Windows is 64 bits only; 32-bit Windows GUI builds are not off
 
     There is no more need to download some special installer from the Qt website, the standard MSYS2 package for Qt will do in almost all circumstances.
 
+    **Note:** There is a known issue that GUI won't lauch properly when building tag v0.13.0.3 with Qt 5.11.2.
+    
+    If your encounter issue with that, please remove current Qt by: `pacman -R mingw-w64-x86_64-qt5`
+    
+    And install 5.11.1 instead by: `pacman -U http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-qt5-5.11.1-3-any.pkg.tar.xz`
+
 5. Install git
 
     ```