Dash by plotly,

Hi everyone,
I have many issues with dash since yesterday, an idea about where the problem comes from? here is the error

  • Running on http://127.0.0.1:8050/ (Press CTRL+C to quit)
    127.0.0.1 - - [27/Mar/2019 09:50:14] “GET / HTTP/1.1” 200 -
    127.0.0.1 - - [27/Mar/2019 09:50:16] “GET /_dash-layout HTTP/1.1” 200 -
    127.0.0.1 - - [27/Mar/2019 09:50:16] “GET /_dash-dependencies HTTP/1.1” 200 -
    [2019-03-27 09:50:16,188] ERROR in app: Exception on /_dash-update-component [POST]
    Traceback (most recent call last):

127.0.0.1 - - [27/Mar/2019 09:50:16] “POST /_dash-update-component HTTP/1.1” 500 -
127.0.0.1 - - [27/Mar/2019 09:50:16] “POST /_dash-update-component HTTP/1.1” 200 -