# Connection error when start dashboard after upgrade to 0.19.1

**URL:** <https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493>\
**Category:** Dashboard\
**Created:** [22 August 2018 21:27 UTC](https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493 "2018-08-22T21:27:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![petrho](https://avatars.discourse-cdn.com/v4/letter/p/5e9695/32.png) [@petrho](https://discourse.nodered.org/u/petrho)\
**Post date:** [22 August 2018 21:27 UTC](https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493/1 "2018-08-22T21:27:17Z")

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After upgrade to 0.19.1 (windows) I often get connection lost error flashing in red when start the ui. When closing the browser and test again it works.

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**Author:** ![sebakrau](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@sebakrau](https://discourse.nodered.org/u/sebakrau)\
**Post date:** [23 August 2018 14:09 UTC](https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493/2 "2018-08-23T14:09:02Z")

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Same for me. Could fix the error by downgrading the node red dashboard from version 2.9.6 to version 2.9.5. Looks like Issue #411 which was fixed by upgrading the [socket.io](http://socket.io) lib does not always work.

If you want to downgrade the dashboard:

```
cd ~\.node-red
npm i node-red-dashboard@2.9.5

```

Then restart node red service.

@dceejay

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [23 August 2018 19:17 UTC](https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493/3 "2018-08-23T19:17:45Z")

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You need to make sure you flush the cache in the browser when you upgrade so that the socket library matches the one at the server end.

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**Author:** ![sebakrau](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@sebakrau](https://discourse.nodered.org/u/sebakrau)\
**Post date:** [24 August 2018 09:37 UTC](https://discourse.nodered.org/t/connection-error-when-start-dashboard-after-upgrade-to-0-19-1/2493/4 "2018-08-24T09:37:06Z")

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Thank you! It works now also in 2.9.6 for me. I had to clear the cache and stop and restart firefox. Now everything is as expected!