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.
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 (https://nightly.mozilla.org/) 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 (https://goo.gl/AR5o9d).
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.