@Sullyman The state of the panels is saved along with the user data, and it might be that something accumulated there and causes this slow down. on Window, with VS exited, go to the c:\Users<user_name>\AppData\Local\NumericPath\VectorStyler1.2\vector\data\resources\ folder, and (back up first) remove these files, then start VS. This will restore all panel state and user settings to defaults.