You are using a Beta 58.0 that is to be expected.

You could try this please : Go the 3 Bar Menu then Options --> General --> Performance and untick everything. change the recommended size lower then see how it runs. Note: 0 = No Multiprocessor = slow again. Try 2 Restart Firefox after making these changes please.

Please let us know if this solved your issue or if need further assistance.

Thank you for your quick response Pkshadow.

I apologise for not explaining well. I have been experiencing these issues with Firefox Quantum 57 (Stable release) for weeks now. I only installed Nightly yesterday because Firefox has been the only browser to accommodate my browsing habits for years and I would like to contribute if possible. I also thought v59 might have solved some of the issues 57 has but it appears not to be the case.

I tried the solution you suggested first in Nightly. Sad to say Nightly went back to freezing tabs within an hour.

I was skeptical it would work in 57 but I tried anyway, and it worked... for about 6hrs before everything started to break again.

Other things I've tried since yesterday: - Installed a GPU driver update but it was incompatible with my device and I was not able to find an update on the manufacturer's website (I will try again tomorrow when I'm less tired). - Downloaded and ran Malwarebytes - nothing. - 7hrs into a full scan with Windows Defender - nothing for now. - Thought I might have Vundo for a couple hours based on some Mozilla Support page but this should be unlikely since I have never had pop-ups.

I am exasperated to say the least. Waterfox seems to be ok though so I might give up this unrewarding endless search if this doesn't help:

I ran into a thread where it was suggested that all Plugins be deactivated but I'm unsure whether any of the following are needed: OpenH264 Video Codec provided by Cisco Systems Widevine Content Decryption Module provided by Google Inc.

Should I deactivate them and could this be the problem?

Btw I also tried Gmail in Quantum on a new computer that had 8GB RAM and wow at the speed. Unfortunately my laptop only has 4GB. I find it hard to believe that FF could accommodate up to 300 tabs before freezing prior to 57 and now it cannot despite boasting about its lower RAM usage and faster speeds.

Not sure if this is related, but Nightly tells me I have 122 unsent crash reports - I assume these include FF crash reports since they go back to 2015.

By my count there are 124 reports since Nov 2017, and 31 reports from Jan 2015 - Oct 2017.

Of the 124 reports since November, 20 of them are dated 14 Dec (yesterday, which is when I installed Nightly). On other days the reports vary from 2-10, almost on a daily basis.

Not sure if the sudden increase in crashes is related to the multiple processes running in 57+ or if old reports get deleted? Regardless, the fact that FF crashed almost every day is alarming.

Is there any known reason for this?

Just to reply Gmail works fine for me on FF57.0.2 including yutubbers. So I doubt FF is causing this. How was your FF installed or upgraded and was the previous FF x86 or x64?

Yes, I tried Gmail on another computer (brand new) that has 8GB of RAM and Quantum worked amazingly fast. But it did cause the memory usage to be over 50% there so I figured 4GB is no longer enough these days! I don't use Youtube much but I don't remember it being worse than other pages when I did.

But you posed and interesting question and I just checked.

I have x64 for both Stable and Nightly, but the Mozilla Firefox folder is located in Program FIles (x86) whereas Nightly's folder is in Program Files. Does this mean I used to have FF x86 and at some point it changed into x64? Or does the MF folder always go into x86? I can't figure out how to check whether I used to have FF x86 but I don't think it's very likely.

Firefox autoupdated to 57 in November or so. I've had it installed for years. Nightly was installed from the official website a couple days ago.

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Hello again,

Thank you all for your help.

I believe Pkshadow's suggestion must have ended up working because Quantum 57 has been working pretty well for the past 3 days. Not sure why it didn't work immediately and only after taking a 2-day break during which I used Waterfox.

No more issues with Gmail which was the biggest problem I was having. Browser still freezes and crashes after a day's work but I haven't lost tabs in the process so for now I can bear with this. Haven't tried having 100 tabs yet though.

Might give Nightly another try soon and if it goes well I may switch to it permanently.

Anyhow, thank you all for your patience and suggestions. Greatly appreciated! :)