1721400 - Firefox 90 pages not completing loading intermittently

Status: RESOLVED WORKSFORME

(Core :: Networking, defect)

Description

[ventsyv]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:90.0) Gecko/20100101 Firefox/90.0

Steps to reproduce:

Macbook Pro (16-inch, 2019), macOS Big Sur 11.4

Open 10 - 15 tabs, navigate to a some pages and leave them open for a while. It usually happens after a few hours or if I leave the machine on overnight, but occasionally it takes as little as 1 - 2 hours.

Actual results:

After a while certain sites will stop loading fully.
For example, on lichess.org the quick pairing table on the main page will not load the text and is not clickable.

Similar issue with Jira (running on a private server) and other sites.

Restarting the browser usually fixes the problem.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Networking' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Kershaw Chang [:kershaw]]

Hi Reporter,

Could you try to get the http log when this happens?

Thanks.

Comment 3

[ventsyv]

Attachment: Screen Shot 2021-07-22 at 12.49.50 PM.png

Here is a screenshot of the behavior I'm seeing.

Comment 4

[ventsyv]

Attachment: HTTP log

Log includes trying to load lichess.org and the internal Jira instance. Both failed to fully load.

Comment 5

[ventsyv]

Opening a new tab or a new window does not work, but opening a new PRIVATE window does fix it in that window.

Comment 6

[Kershaw Chang [:kershaw]]

Thanks for the log.
However, I can't find anything obvious wrong in the log. It seems most of requests were read from cache.
Can you reproduce this with a clean profile or when cache is disabled?

Comment 7

[ventsyv]

If I open an incognito tab everything works just fine. I assume that's a clean profile right?

Comment 8

[Kershaw Chang [:kershaw]]

(In reply to ventsyv from comment #7)

If I open an incognito tab everything works just fine. I assume that's a clean profile right?

It's not exactly the same. In private mode, Firefox doesn't read/write data from disk cache.
If you create a new profile and reload the same websites for few times without seeing this problem, maybe the cached file in your old profile is corrupted. Or you could just clean your cache and see if this problem still exists.

Comment 9

[ventsyv]

OK, I'll give that a try next time it happens. Might be a day or two - it's kind of irregular.

Comment 10

[ventsyv]

I signed out of my profile, but problem remains. I cleared the cache - problem remained. I opened a new window just to make sure - problem remained. It looks to me that javascript stops working when it happens.

Comment 11

[ventsyv]

Attachment: firefox_working-main.37595.moz_log

Here is a single refresh of lichess.org after the browser was restarted.
I'll include another with clear cache once it breaks again.

Comment 12

[ventsyv]

OK, here is the log of a single lichess.org request with the cache cleared and signed out of my profile.

Comment 13

[Valentin Gosu [:valentin] (he/him)]

If this is caused by a service worker you can usually see it the the devtools console.
Press Cmd-Shift-J. If there are any messages about failed requests please paste them here.
Thanks!

Comment 14

[ventsyv]

I'm now on FF 92.0 and I'm not seeing the issue anymore.
I'll keep and eye out for it for another week or two but if it doesn't re-occur I'll close this ticket.

Comment 15

[Kershaw Chang [:kershaw]]

(In reply to ventsyv from comment #14)

I'm now on FF 92.0 and I'm not seeing the issue anymore.
I'll keep and eye out for it for another week or two but if it doesn't re-occur I'll close this ticket.

I'd close this bug for now. Please reopen if you see this again. Thanks.