Kivy: White screen when trying to run a kivy app on Raspberry Pi

Question

I am new with Kivy programming and I am working on a project for my college. I have a Raspberry Pi 2 with a 16Gb SD Card and I have installed Raspbian Jessie and Kivy 1.9.2.

I wrote a simple code which is basically just a screen manager. There are six buttons and every button opens a new screen. (the screens contains just a text and a "back" button at this moment) This kivy app works fine in my computer (windows 7) but when I try to run it with raspberry pi I only get a white empty screen. (I don't have any error message on CLI when I run the app)

I tried some other kivy apps like "showcase" from the examples folder of kivy and it worked fine. I tried to run a lot of examples from kivy and I noticed that some apps work fine and others just give a blank screen. Any ideas? Is there a RAM situation? Thanks!

from kivy.app import App
#kivy.require("1.9.2")
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from glob import glob
from os.path import dirname, join, basename
from kivy.uix.screenmanager import ScreenManager, Screen, WipeTransition
from kivy.uix.label import Label
from kivy.uix.widget import Widget
from kivy.uix.videoplayer import VideoPlayer
from kivy.clock import Clock
from kivy.graphics import Line,Color,Ellipse


class MainScreen(Screen):
   pass

class ScreenOne(Screen):
   pass

class ScreenTwo(Screen):
   pass

class ScreenThree(Screen):
   pass

class ScreenFour(Screen):
   pass

class ScreenFive(Screen):
   pass

class ScreenSix(Screen):
   pass

class ScreenManagement(ScreenManager):
   pass

presentation = Builder.load_file("Interface4.kv")

class Interface4(App):
   def build(self):
    return presentation

if __name__ == "__main__":
   Interface4().run()

Interface4.kv

#: import WipeTransition kivy.uix.screenmanager.WipeTransition

  ScreenManagement:
    transition: WipeTransition()
    MainScreen:
    ScreenOne:
    ScreenTwo:
    ScreenThree:
    ScreenFour:
    ScreenFive:
    ScreenSix:

Everyone of these screens contains just the basic texts and a "back to previous screen" button. For example.

<ScreenOne>
name: "other1"
orientation: 'vertical'
canvas:
    Color:
        rgb: 0, 0, 1
    Rectangle:
        source: 'data/images/background.jpg'
        size: self.size
FloatLayout:        
    Button:
        on_release: app.root.current = "main"
        background_color: 0,0,1,0
        text_size: self.size 
        font_size: 20
        pos_hint: {'x': .85, 'y': .0}
        size_hint: .15, .15
        Image:
            source:'data/images/home.png'
            pos:self.parent.pos
            size:self.parent.size

Answer 1

This problem is related to the GPU memory on the Raspberry Pi. You can increase it.

Edit /boot/config.txt

Scroll down until you see gpu_mem and change it as follows:

gpu_mem=256

Then reboot.