Hi Dagster newbie here I am trying to follow the tutorial bu

Question

Hi Dagster newbie here I am trying to follow the tutorial but I ran into this issue when spinning up Dagit UI ```werkzeug routing WebsocketMismatch 400 Bad Request The browser or proxy sent a request that this server could not understand ``` Does anyone has a clue why this might happen

daniel · Answer

Hi Dan did you install dagster dagit via pip If so I d be curious what version of Flask you have installed You can check via ```pip freeze | grep Flask```

Dan Zhao · Answer

I installed via Poetry which is essentially pip

Dan Zhao · Answer

and the package version is flask 2 0 1 A simple framework for building complex web applications flask cors 3 0 10 A Flask extension adding a decorator for CORS support flask graphql 2 0 1 Adds GraphQL support to your Flask application flask sockets 0 2 1 Elegant WebSockets for your Flask apps

daniel · Answer

Got it thanks I m not deeply familiar with poetry but dagit should be pinned to flask lt 2 0 0 if you re using a recent version of dagster I think the error you re seeing is due to that incompatibility Did you get any warnings or errors when you were installing

Dan Zhao · Answer

Ah understood thanks Daniel I ll try downgrading flask No I didn t see any warnings when installing

daniel · Answer

Hm I m not sure why that would be the pin is here <https github com dagster io dagster blob master python modules dagit setup py L54> The two relevant pins there are Flask lt 2 0 0 and Werkzeug lt 2 0 0

Dan Zhao · Answer

Just tried with downgrading flask works like a charm Thanks again I guess I could have conflicting version requirements and I somehow misused poetry