TypeError: isdeleted() argument 1 must be sip.simplewrapper, not PlotWidget

[blipton]

I have the same issue, all the examples crash Python and the console shows an endless stream of errors, like :

File "C:\Python\Python37\lib\site-packages\pyqtgraph\graphicsItems\GraphicsObject.py", line 40, in itemChange
ret = sip.cast(ret, QtGui.QGraphicsItem)
TypeError: cast() argument 1 must be sip.simplewrapper, not PlotItem
TypeError: isdeleted() argument 1 must be sip.simplewrapper, not ViewBox


I've tried reinstalling sip and PyQt5==5.12.0/1/2 - 5.15, but no luck. Interestingly, aside from your post, I haven't found anyone else have this problem!

>>> from PyQt5 import QCore, QtGui, QtWidgets, uic
>>> from PyQt5.QtWidgets import QApplication
>>> import pyqtgraph as pg
>>> pg.__version__
'0.11.1'
>>> app = QtGui.QApplication([])
>>> pg.plot()