Browser kept crashing when several tabs were open, particularly if there were two or more PDF documents displayed in respective tabs. System memory is fine.




2 years ago
2 years ago


(Reporter: kaiasrex, Unassigned, NeedInfo)


52 Branch

Firefox Tracking Flags

(Not tracked)



(1 attachment)

166.60 KB, text/plain


2 years ago
Created attachment 8859678 [details]
raw dump.txt

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20170323105023

Steps to reproduce:

1. I was browsing the internet, searching for PDFs on programming via Google, GitHub etc. 
2. I had several webpages open and I started reading PDF documents downloaded or accessed via the web (programming texts books searched for via Google). 
3. The PDF documents were generally 500+ pages; and
4. I think I had at most 3-4 tabs with PDFs open in them, the rest were normal webpages.

Actual results:

1. When I switched over from one PDF to another, or to a site, the response time started to lag.
2. After a couple of seconds the system just came to a halt..
3. I was able to move my cursor but there was no response from any action.
4. I tried ctrl+alt+del; ctrl+shift+esc; alt+f4; clicking various tabs, start button etc, nothing responded.

Expected results:

1. The system should have informed me of the increased memory allocation reaching critical;
2. then it should have offered me the choice of closing unused/least used tabs; high memory items; or
3. the option to cache the tabs, or bookmark them for easier recollection; and/or
4. the option to close the PDF tabs and initiate a download instead to a nominated folder.
This is not a security issue.
Group: firefox-core-security
User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0

I have tested your issue on latest Firefox release v53.0 and latest Nightly (Build ID: 20170424030211) and could not reproduce it. I've opened 7 tabs with normal webpages and 5 tabs with PDF docs from 300 pages to 2050 pages. From the User Agent I can see that you are using a 32-bit Firefox version on a 64-bit system. Can you please try with the 64-bit Firefox version? Can you provide the links to the documents that created this issue?

Is this still reproducible on your end ? If yes, can you please retest this using latest FF release and latest Nightly build ( and report back the results ? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (
Flags: needinfo?(kaiasrex)
Considering the fact that I cannot reproduce this and the fact that the reporter did not answered to my request until now, I will mark this as Resolved-Worksforme.

If anyone can still reproduce it on latest versions, feel free to reopen the issue and provide more information.
Last Resolved: 2 years ago
Resolution: --- → WORKSFORME
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