Please check connection, Mattermost unreachable after upgrade to 9.11

[nestho (Ghader)]

Hello
I just upgraded last night to version 9.11 and after that just getting this error :

" Please check connection, Mattermost unreachable. If issue persists, ask administrator to check WebSocket port."

it seems work little bit i mean
we can send message
recieve message
but did not get notification
and did not get message until refresh the mattermost
what i have to do ? any suggestion ?

[john.oliver]

Did you upgrade from 7.something? Integrations configuration settings - Mattermost documentation should be what you need.

[nestho (Ghader)]

no i just upgraded from 9.10 to 9.11

[jprusch1 (Jan Rusch)]

We had no issues when upgrading from 9.10. to 9.11.
Are you using a specific method? We upgrade manually, as described in
https://docs.mattermost.com/upgrade/upgrading-mattermost-server.html

[john.oliver]

What does AllowCorsFrom say?