Slack failing to open with NS_ERROR_DOM_ABORT_ERR error

I use Firefox as my primary browser (version 84 as of today). As part of this, I keep logged into a number of slack channels. These are some of my favorite communities and I go there to chat with folks, learn about interesting topics and hunt for neat links to resources I didn’t know about. Occasionally I’ll even ask a question or two.

Recently, I saw some weird behavior. The slack channels weren’t updating. The notice at the bottom of the browser bar was something like “Slack is trying to connect”.

Hmm, I thought, that’s weird. I tried reloading the page. I couldn’t do it. That is, even hitting control-f5 didn’t change anything. However, I could open other website just fine.

I tried quitting all my browser tabs and restarting. Made sure Firefox was up to date. Checked the Slack status page to see if slack was down. Opened a new tab and typed the slack channel url into the address bar.


So, I popped open the dev tools and looked at the network tab. I saw this error when loading


That turned up this bug. From a scan, several other folks where having this issue, with slack and other sites. This comment shared the solution:

Clearing storage for fixed the issue, and the Slack workspace loads correctly now.

All I had to do was clear the storage for and Slack started working again, magically. Even though I was warned that it might force me to log in again, I didn’t have to do so.

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