Rasa X hangs on rasa-demo

When I run the command “rasa x” for the rasa demo bot, my browser opens a new tab with the displayed URL http://localhost:5002/conversations and the browser hangs with the left panel displaying “Loading conversations” and the right panel displaying “Loading messages”. An animated progress circle is displayed in both panes. The terminal output is:

Your decision has been stored into /home/waldenj/.config/rasa/global.yml.
Starting Rasa X in local mode... 🚀
/home/waldenj/anaconda3/envs/rasa-demo/lib/python3.7/site-packages/tensorflow/python/framework/dtypes.py:528: FutureWarning: Passing (type, 1) or '1type' as a synonym of type is deprecated; in a future version of numpy, it will be understood as (type, (1,)) / '(1,)type'.
 _np_qint16 = np.dtype([("qint16", np.int16, 1)])
The server is running at http://localhost:5002/login?username=me&password=ac7NXlA43z0a

The FutureWarning is displayed many more times before, between, and after the output above, with different line numbers.

The rasa demo repository was cloned today with

git clone https://github.com/RasaHQ/rasa-demo

I’m running rasa inside a conda virtual environment named rasa-demo on Ubuntu 16.04. The python version is 3.7.3. When I installed Rasa and RasaX with pip install rasa-x -i https://pypi.rasa.com/simple, I received the following errors:

ERROR: rasa-demo 1.1 has requirement rasa==1.0.9, but you’ll have rasa 1.2.4 which is incompatible. ERROR: rasa-demo 1.1 has requirement requests~=2.21.0, but you’ll have requests 2.22.0 which is incompatible.

What can I do to get Rasa X to run without hanging on the rasa demo?