For anyone having these kinds of issues with PsychoPy 3, downgrading pyglet may again be the solution. I had a similar problem when using PsychoPy 3.2.3 with pyglet 1.4.4, but no trouble after switching to pyglet 1.3.2.
For anyone having these kinds of issues with PsychoPy 3, downgrading pyglet may again be the solution. I had a similar problem when using PsychoPy 3.2.3 with pyglet 1.4.4, but no trouble after switching to pyglet 1.3.2.