When opening a scene when an unknown plugin exists Errors have occurred while reading this scene that may result in data loss. Will come out.
It can be queried and removed by using the unknown Plugin of the command newly added in 2016, and it will not throw an error when opening the scene.
I wrote the code assuming that there are multiple unknown plugins.
DeleteUnknownPlugin.py
import maya.cmds as cmds
add=0
#Lists unknown plugins in the scene.
unPl = cmds.unknownPlugin( q=True, l=True )
try:
for i in unPl:
print unPl[add]+' is Remove.'
#Removes the specified unknown plugin from the scene
cmds.unknownPlugin( unPl[add], r=True )
add += 1
except:
print 'UnknowPlugin is none.'
This will remove the unknown plugin from the scene.