Mozilla has recently decided to delay the 64-bit version of Firefox for Windows, as it still struggles to address a sandbox issue that's very unlikely to be fixed in time for the release of version 41.
If you're a tech-savvy user who reads industry news every day, this isn't probably the first time you hear the phrase “Mozilla delays Firefox 64-bit for Windows.” Because, truth be told, it's not the first time we say it.
Mozilla has a long history of Firefox 64-bit problems, and just as gHacks writes, it all started in 2010, when the company officially pushed this version of the browser to the Nightly channel.
Nightly is the very first stage of development of each new version of Firefox and is generally considered highly unstable. Once a version is improved enough to be out of Nightly, it's pushed to Beta, another channel where it also receives beta testing and is thoroughly analyzed before eventually getting the green light as stable.
But in the case of the 64-bit version of Firefox for Windows, the story isn't really that simple. Released for the first time in 2010 as a Nightly build, Firefox 64-bit was removed in 2012, but it nevertheless got released to the same channel soon after that.
Two years later, Mozilla made it public that it wanted to roll out Firefox 64-bit for all channels, but in addition to several delays, only the Beta and Nightly rings actually got it.
And this time, Mozilla does it again, as a bug called "Turn on the NPAPI process sandbox for Windows 64-bit by default" blocks the new version of Firefox from working correctly on Windows. A statement offered by Mozilla explains everything:
“The sandbox regressions only affect 64-bit Firefox users. We won't ship 64-bit Firefox until the sandbox works, so we won't be shipping 64-bit with Firefox 41 anyways.”
So here you are, Firefox 64-bit for Windows won't be here with Firefox 41, so your only option right now is to stick to the 32-bit. Additionally, you can always give a try to Beta and Nightly, both of which come with a 64-bit version, but keep in mind that bugs and issues are likely to be found.
Of course, all versions are here on Softpedia too, so go ahead and download Firefox for Windows right now.