app/ui/icons.qrc

@@ -1,6 +1,5 @@
 <RCC>
   <qresource prefix="icons">
-    <file alias="musicmuster">musicmuster.png</file>
     <file alias="stopsign">stopsign.png</file>
     <file alias="wikipedia">wikipedia-logo.png</file>
     <file alias="songsearch">songsearch_icon.png</file>

app/ui/main_window.ui

@@ -14,8 +14,8 @@
    <string>Music Muster</string>
   </property>
   <property name="windowIcon">
-   <iconset resource="icons.qrc">
-    <normaloff>:/icons/musicmuster</normaloff>:/icons/musicmuster</iconset>
+   <iconset>
+    <normaloff>../../musicmuster.png</normaloff>../../musicmuster.png</iconset>
   </property>
   <property name="styleSheet">
    <string notr="true"/>

app/ui/main_window_ui.py

@@ -16,7 +16,7 @@ class Ui_MainWindow(object):
         MainWindow.setObjectName("MainWindow")
         MainWindow.resize(1280, 857)
         icon = QtGui.QIcon()
-        icon.addPixmap(QtGui.QPixmap(":/icons/musicmuster"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
+        icon.addPixmap(QtGui.QPixmap("ui/../../musicmuster.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
         MainWindow.setWindowIcon(icon)
         MainWindow.setStyleSheet("")
         self.centralwidget = QtWidgets.QWidget(MainWindow)