PsychoPy won't open on mac OS Sierra

I upgraded to mac OS Sierra last night. Now, PsycoPy won’t open. I am running version 1.84.2. The splash screen shows up, disappears, and then I get this error:

If I start in the Finder window and open a PsychoPy experiment (.psyexp file), I get the same errors.
If I start in the Finder window and open a script (.py), psychopy opens, as evidenced by toolbar options appearing at the top of the screen, but there are no visible windows.
Selecting View > Go to Builder View does nothing.
File > Open either .psyexp or .py files also does nothing.

Has anyone else run into an issue like this?

Thanks in advance!

What does it say when you click on the button to view the console?

Process: security id
Message: no db or old db version, skipping

EDIT:

I watched the console as I opened Psychopy, and it looks like this is the error that appears:
Detected missing constraints for < private >. It cannot be placed because there are not enough constraints to fully define the size and origin. Add the missing constraints, or set translatesAutoresizingMaskIntoConstraints=YES and constraints will be generated for you. If this view is laid out manually on macOS 10.12 and later, you may choose to not call [super layout] from your override. Set a breakpoint on DETECTED_MISSING_CONSTRAINTS to debug. This error will only be logged once.

I am having a similar problem, but in my case PsychoPy does not start at all. The app icon comes up in the dock and it disappears after a second. I tryed with version 1.84.1 and still had the same issue.

That is how my problem began and it sort of evolved into what I describe here:

The solution that worked for me (described in the link above) was to delete the entire ~/.psychopy2 folder. It works perfectly now!