# Spawn server error

**URL:** <https://discourse.jupyter.org/t/spawn-server-error/19304>\
**Category:** discuss\
**Tags:** jupyterhub, help-wanted\
**Created:** [May 9, 2023, 1:01am UTC](https://discourse.jupyter.org/t/spawn-server-error/19304 "2023-05-09T01:01:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![caiquanyou](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/caiquanyou/32/5526_2.png) [@caiquanyou](https://discourse.jupyter.org/u/caiquanyou)\
**Post date:** [May 9, 2023, 1:01am UTC](https://discourse.jupyter.org/t/spawn-server-error/19304/1 "2023-05-09T01:01:09Z")

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I start a new server on Jupyterhub, and get this errer below:  
Error: HTTP 500: nternal Server Error (Error in Authenticator.pre spawn start: TypeError unsupported operandtype(s) for +: ‘NoneType’ and ‘list’)

hub use dockerspawner, and no container is started when this error comes, the image I use is the custom jupyter image which I custom the start.sh to change the gid and uid  
Any help would be appreciated

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**Author:** ![manics](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/manics/32/85_2.png) [@manics](https://discourse.jupyter.org/u/manics)\
**Post date:** [May 11, 2023, 8:51am UTC](https://discourse.jupyter.org/t/spawn-server-error/19304/2 "2023-05-11T08:51:52Z")

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Please could you give us enough information to reproduce your error? For example, your versions of JupyterHub and other components, how you’ve installed everything, your config files, etc?