User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0 Build ID: 20160726073904 Steps to reproduce: Right click in the taskbar icon > Open a new Private Window. Actual results: It takes 3 seconds in the white page then 2 seconds to load the "purple Private page" with E10S activated. Without E10S it opens almost instantly. Expected results: Opening "Normal Mode" with E10S activated is as fast as with it not activated. "Private Mode" should behave the same way.
Marcos, can you reproduce in e10s in safe mode (with all add0ons disabled?) This WFM on on Mac 10.11 with latest Nightly 51.0a1, 20160811030201 (Multiprocess Windows : 1/1 (Enabled by default))
When I start Firefox in Private Mode + Safe Mode (all addons disabled) the issue DOES NOT occur. When I create a new clean profile, change ONLY the parameters below of 'about:config' and close/start it in Private Mode the issue OCCURS: browser.tabs.remote.autostart=true extensions.e10sBlockedByAddons=false extensions.e10sBlocksEnabling=false browser.tabs.remote.force-enable=true
Marcos, thanks for checking. This is likely caused by an add-on, please attach your about:support
tracking-e10s: ? → +
Created attachment 8780209 [details] 2016-08-11_about_config.txt I uninstalled "Free Memory 2.0" addon and it got 1~2 seconds faster to start, although it's slower than 'Normal Mode' with or without the addon installed. about:support attachment: 2016-08-11_about_config.txt.
Marcos, is there any chance you could try narrowing it down to one addon?
Uninstalling AdBlock Plus makes it 0.5 ~ 1.0 second faster to start the browser in Private Mode. I couldn't disable Kaspersky Addon. With all addons, including Free Memory 2.0, it opens instantly in 'Normal Mode'.
can QA test adblock plus in private browsing mode (latest version). shouldn't be suspect - but validate. then kapersky
User Agent Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0 Build ID 20160726073904 Hi, I tried to reproduce the issue with AdBlock Plus 2.7.3 installed but it worked fine for me. I also installed Free Memory 2.0 add-on but still I could not reproduce the issue. I wanted to check Kaspersky too, but I could not find the addon, I guess Kaspersky antivirus has to be installed on the machine previously (privilege that I don't have). I have tried on Firefox 48 (pt-BR) and Firefox 49.0.1 (en-US) on Windows 7 x64 with the preferences from comment 2.
Marcos, can you still reproduce the issue on latest release (49.0.1) or latest Nightly ?  https://nightly.mozilla.org/
Created attachment 8801115 [details] 2016-08-11_about_support.txt Firefox 49.0.1: * Private Mode: takes about 3 seconds to be able to type on address bar; * Normal Mode: takes almost 2 seconds to be able to type on address bar.
Comment on attachment 8780209 [details] 2016-08-11_about_config.txt Marked as obsolete because there's a new updated attachment regarded to about:support information.
Attachment #8780209 - Attachment is obsolete: true
With Firefox 57 only WebExtensions are permitted and are, by default, e10s compatible.
Status: UNCONFIRMED → RESOLVED
Last Resolved: 11 months ago
Resolution: --- → INCOMPLETE
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