no module named "XPLMdefs" found

[Pikotaro]

C:\Program Files (x86)\Steam\steamapps\common\X-Plane 11\Resources\plugins>PI_FreeSharedCockpit_pluginMaster.py
Traceback (most recent call last):
File "C:\Program Files (x86)\Steam\steamapps\common\X-Plane 11\Resources\plugins\PI_FreeSharedCockpit_pluginMaster.py", line 1, in
from XPLMDefs import *
ModuleNotFoundError: No module named 'XPLMDefs'