If you did not create your QGIS plugin using the latest version of QGIS Plugin Builder, you might find yourself encountering this error when running your plugin in QGIS specially if you have a resources file for images/logos that you included in your plugin.

ImportError: No module named resources_rc

This error seems to stem from the fact that when you have resources in your GUI from resource.qrc, the following lines are added to your .ui files:

<resources>
  <include location="resources.qrc" \>
</resources>

One of the solutions for this issue is by removing the said line in the .ui files and replacing them with:

<resources \>

then compiling the .ui files to .py files using pyuic.

However, my simpler solution involves just one command. Since python is looking for a resources_rc module, all I did was compile my resources.qrc to resources_rc.py instread of resources.py.

pyrcc resources.qrc -o resources_rc.py

And viola, my plugins worked and the images I added to the GUIs were all present.