Flask Admin Incompatible With Modern Flask ( >=2.3)

[mwheeler1982]

I get the following error message when trying to start flask-admin . Based on my research, it looks like this has been broken since Flask 2.3. It looks like warnings were introduced in 2.2.0 that it was deprecated, then officially removed in 2.3.0 .

See here: https://flask.palletsprojects.com/en/3.0.x/changes/#version-2-3-0 and here: pallets/flask#4692 .

Traceback (most recent call last):
File "/Users/user/venv/flask-admin-test/test.py", line 4, in
app = AdminApp()
File "/Users/user/venv/flask-admin-test/lib/python3.9/site-packages/flask-admin-test/app.py", line 129, in init
self.init_flask_app()
File "/Users/user/venv/flask-admin-test/lib/python3.9/site-packages/flask-admin-test/app.py", line 300, in init_flask_app
from flask.json import JSONEncoder
ImportError: cannot import name 'JSONEncoder' from 'flask.json' (/Users/user/venv/flask-admin-test/lib/python3.9/site-packages/flask/json/init.py)

[maxnoe]

@mwheeler1982 The error is in your app code, not in flask-admin