Summary
Mattermost’s Slack importer imports messages twice in every channel. https://i.zelakto.tv/Urbq9c4.png
Steps to reproduce
Fresh Mattermost install running v4.4.3 on CentOS 6.
Expected behavior
Importer doesn’t duplicate messages.
Observed behavior
Importer duplicates messages, when noticed, Mattermost took a while to load messages in desired channel. I restarted the server (which killed the import) and tried again, this appears in console.
2017/12/12 03:24:48 http: multiple response.WriteHeader calls
[2017/12/12 03:24:48 EST] [EROR] websocket connect err: websocket: not a websocket handshake: 'upgrade' token not found in 'Connection' header
[2017/12/12 03:24:48 EST] [EROR] /api/v4/websocket:connect code=500 rid=za3sep9cgpy8xcupdfdo1yi8oo uid=pdgbziwhjfdq9mqar3nuqqbhac ip=IPADDRESS Failed to upgrade websocket connection [details: ]
With this, Mattermost becomes unresponsive, then I have to wipe the MySQL database.
Any help would be much appreciated, thanks!