Apache Airflow : airflow initdb results in "ImportError: No module named json"

The problem is known, and is described here, in the ASF Mail Archives

We removed the incompatible Werkzeug library from apache master this weekend. It caused Airflow installations to fail.

To resolve, manually install the werkzeug library in a correct version:

pip install werkzeug>=0.15.0

As explained in the mail list, this seems to be a temporary problem, and this solution is a workaround. The problem is encountered in version 1.10.3.


Just upgrade flask. You can use this command:

sudo pip install --upgrade Flask