Summary mattermost client alert a red bar on the top ,shows Please check connection, Mattermost unreachable. If issue persists, ask administrator to check WebSocket port Steps to reproduce My site is mattermost 5.19.1 on windows 2016 with reverse proxy on IIS <config.json> { “ServiceSettings”…

Have you had a chance to take a look at our troubleshooting docs https://docs.mattermost.com/install/troubleshooting.html#please-check-connection-mattermost-unreachable-if-issue-persists-ask-administrator-to-check-websocket-port ?

Thks for the reoly,the article did not help, I use IIS with the websocket installed ( not using NGINX as proxy) Configure reverse proxy by the following steps 1.Download the URL Rewrite 2.0 x64 module. 2.Download the Application Request Routing 3.0 x64 module. 3.Install the modules (trivial in…

Is there any solution for this problem ? The troubleshooting docs did not help Is there any advice provided by your team?

@ahmaddanial Are you familiar with this issue?

Hello, @amy.blais @robert9780 Can you check on your developer tools to verify that the header and origin match each other? For example, this is what I see when I am logged in to community.mattermost.com: [Screenshot 2020-02-14 at 07.16.54] If not, you’ll need to add the origin to your AllowCors…

[errorPage01] As the pictures shows , the Host and Origin matches , and the IIS URL rewrite setting like below [errorPage02] Is this means the IIS reverse proxy forward the right headers? If so , the problem is still there. It’s so upset…

You are most welcome, @robert9780 Any time!

I’m also facing same issue only in mobile browser . Desktop/browser apps is not showing the error. I have added AllowCorsFrom to *. But no luck. Any help ?

hi robert， I have the same issue, can you help me to sovled this problem? thanks a lot

In the system console of your Mattermost instance, in the CORS configuration section, add a * to the record, and click save. This should fix it, according to Post #8

Failed to upgrade websocket connection

Troubleshooting

robert9780 (robert lo) February 14, 2020, 8:48am 8

@ahmaddanial
I add the origin to ‘AllowCorsFrom’ parameter in config.json and it works!
Thanks for your help!

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Failed to upgrade websocket connection

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