hmm... something must went wrong. I can't see it at all.
creating a Pyplug node with Shadertoy inside returns me error messages, though it worked well before upgrade.
While executing script:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/home/han/.Natron/BlenderLensDistortion.py", line 232, in createInstance
AttributeError: 'NoneType' object has no attribute 'setScriptName'
Will try to reinstall 2.2.6 again.