Attempt to workaround problem reported about empty plc.xml after unrelated crash. Now, if etree model is corrupted in a way tostring() would generate an empty string, exception prevents saving.
from __future__ import absolute_import
from etherlab.etherlab import *
from util.BitmapLibrary import AddBitmapFolder
import util.paths as paths
AddBitmapFolder(os.path.join(paths.AbsDir(__file__), "images"))