Hi I'm running into a similar error as mentioned before but all my modules seem to be installed correctly:
I am running on python 3.9.3, vispy 0.6.6, and PyQt5 5.15.4. Do you know if they have made changes recently to the modules? Searching through vispy's documentation I haven't been able to find the setParent() function that seems to be causing the problem. However, commenting that line out and the following line that sets the central widget results in a blank graph.
I'm also experiencing this problem, and the issue on the github didn't seem to be relevant. Uninstalling and reinstalling pyqt5 at different versions had no effect on the code's ability to run (aside from making it impossible when the code was not installed). When it is installed, removing the two lines mentioned previously allows the code to run (but without the plotter functioning, though the drone still flies) and with them present I receive the same 'CanvasBackend' object has no attribute 'setParent' error.