Error on master when dismissing new messages toast

Description

Environment: master, found during PR testing https://github.com/mattermost/mattermost-webapp/pull/7002
Not exactly sure of the repro steps, wasn't reproducing reliably on the test server and master

Steps:
1) Open Off Topic as user-1
2) Open any thread in the RHS
3) Scroll away from bottom on the main channel view and RHS
4) On a different browser log in as user-2 and post few messages on the same channel from step 1, Off Topic
5) Place focus back on the 1st browser and click on x to dismiss new message toast

Expected: No errors

Actual: Console errors and banner present. I am not sure if it's caused by the actual dismissing of the banner, as it's not reproducing consistently using the same steps

QA Test Steps

None

Activity

Show:
Jelena Gilliam
November 11, 2020, 4:58 AM

re-tested and errors are also present on community 5.28, release and daily

Amy Blais
November 11, 2020, 5:00 AM

Community is on v5.29-rc1, can you also help check if it's a regression?

Jelena Gilliam
November 11, 2020, 5:25 AM

I am not able to reproduce on 5.28 and 5.27

Jelena Gilliam
December 9, 2020, 10:27 AM

Additional info: This is present on 5.30 and latest cloud (not on master). You only have to hover over X, no need for the click on any new message toast

Caleb Roseland
December 10, 2020, 5:38 AM

possible fix

Mana

None

Assignee

Unassigned

QA Assignee

None

Reporter

Jelena Gilliam

Epic Link

None

Fix versions

Mattermost Team

Sustained Engineering

Sprint

None

Labels

None

QA Testing Areas

None

GitHub Issue

None

Components

None

Severity

None