'Server 500' response when trying to view any of the H5P content

Observed behavior

Server 500 response within the content viewport when trying to view any H5P content imported from H5P Samples channel.

Expected behavior

H5P interactive content should have loaded correctly.

User-facing consequences

Can’t use the content.

Errors and logs

Logs herein - kolibri.txt

Steps to reproduce

1. Enable h5p_viewer plugin
2. Restart Kolibri
3. Import content from H5P Samples channel
4. Navigate in Learn to view content

Context

Firefox on Windows 10.

Some information from Device - Info:

OS:                Windows-8-6.2.9200 
Python:            3.4.3
Installer:         Windows
Server:            Kolibri internal server

[rtibbles]

I can fix 2, if you guys can tackle 1.

[cpauya]

For reference, here’s the last few lines of the kolibri.txt log file attached by @intelliant01 above:

INFO 2020-04-28 08:06:44,128 cherrypy.access.115203152 127.0.0.1 - - "GET /static/kolibri.plugins.h5p_viewer.main/kolibri.plugins.h5p_viewer.main-0.13.2.js HTTP/1.1" 200 5730 "http://127.0.0.1:8080/en/learn/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0) Gecko/20100101 Firefox/75.0"
ERROR 2020-04-28 08:06:44,171 exception Internal Server Error: /zipcontent/dda40b9ee291ef85d0911ccba551aba4.h5p/
Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\kolibri\dist\django\core\handlers\exception.py", line 41, in inner
    response = get_response(request)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\core\handlers\base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\core\handlers\base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\views\generic\base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\views\generic\base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\utils\decorators.py", line 67, in _wrapper
    return bound_func(*args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\views\decorators\http.py", line 99, in inner
    response = func(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\utils\decorators.py", line 63, in bound_func
    return func.__get__(self, type(self))(*args2, **kwargs2)
  File "C:\Python34\lib\site-packages\kolibri\core\content\api.py", line 75, in wrapper_func
    response = some_func(*args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\dist\django\views\decorators\clickjacking.py", line 58, in wrapped_view
    resp = view_func(*args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\core\content\decorators.py", line 14, in wrapper_func
    response = some_func(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\kolibri\core\content\views.py", line 269, in get
    response = get_h5p(zf, embedded_filepath)
  File "C:\Python34\lib\site-packages\kolibri\core\content\views.py", line 151, in get_h5p
    h5pdata = json.loads(zf.open(zf.getinfo("h5p.json")).read())
  File "C:\Python34\lib\json\__init__.py", line 312, in loads
    s.__class__.__name__))
TypeError: the JSON object must be str, not 'bytes'

This has the same exception to this issue: https://github.com/learningequality/kolibri/issues/6615 - I’m not sure if they are related or the same @indirectlylit.

@mrpau-richard You may be right that upgrading to Python 3.6 fixes the issue. The Python 3.6 release notes mentions json improvements very similar to this issue.

I reproduced this in Windows 7, Upgrading the Python version from 3.4 to 3.6 will fix the issue on Windows.

Please note however that we had an issue using Kolibri on Windows 10 with Python 3.6 last year: https://github.com/learningequality/kolibri/issues/5733

I see two approaches to this:

1. Test if upgrading to Python 3.6 indeed fixes this issue (and the other one too) and make a PR for such. We hope to enter beta testing soon so we can thoroughly test this “upgrade fix” too.
2. Fix the underlying code as @rtibbles suggested.

Or we can do both 😺