如果我导入 QtWebEngineWidgets，PyQt5 会崩溃

Question

I created a new Anaconda environment with Python 3.6. I installed PyQt5 with pip install PyQt5 . I have this butt-simple program:

from PyQt5 import QtWidgets
#from PyQt5 import QtWebEngineWidgets

app = QtWidgets.QApplication([])

As written, it runs (and does nothing). If I uncomment the QtWebEngineWidgets line, it crashes. If I leave that line uncommented, but comment out the final line, it no longer crashes. In other words, it crashes when trying to create the application, but only if I previously tried to import QtWebEngineWidgets . Importing QtWebEngineWidgets itself doesn't cause a crash unless I try to create an application.

I'm running this on Windows 7. The crash is a "hard" crash: it's not a Python exception, but a Windows popup saying "Python has stopped working". The info says that the crash is in "atio6axx.dll". Googling around I see some hints that there could be some sort of conflict between Qt and my graphics driver, but I don't know how to debug it, let alone fix it. (I have an embedded graphics controller that shows as ATI Radeon HD 4250.)

conda list qt shows:

 PyQt5                     5.8.2                     <pip>

What can I do to be able to use QtWebEngine successfully?

Answer 1

In my experience this issue has nothing to do with PyQt being installed using both pip and anaconda, although this would cause an problem too. If you only have pyqt installed on Anaconda the following code my cause a hard crash:

from qtpy import QtWidgets
from qtpy import QtWebEngineWidgets
app = QtWidgets.QApplication([])

We started experiencing this on a number of computers after an "upgrade" to windows 10, and noticing Spyder stopped working. It exited without an error message. The IT guys tracked it down to the graphics card.

Solutions: downgrade pyqt to version 5.6: conda install pyqt=5.6

Answer 2

I'm seeing this behavior on a windows 10 machine currently as well.
I use qtpy as well but have done this same example in just PyQt5.

Downgraded to 5.6 changes other behavior li