There is a great disturbance among Firefox users who run the browser on old Windows 10 versions. The latest version, Firefox 143, which is currently available in the Nightly Channel, no longer works on pre-1803 versions. When launching the browser on ancient releases, such as Windows 10 version 1703, 1709, or 2015 LTSB, users get the following error:
"The code execution cannot proceed because api-ms-win-core-console-11-2-0.dll was not found. Reinstalling the program may fix this problem."
The discovery quickly sparked discussions among users (who are already unhappy about Mozilla bloating the browser with unnecessary, resource-taxing stuff) about Mozilla dropping old Windows 10 versions, which is not an uncommon thing. Even though Windows 10 overall is still supported, many apps no longer work on very old releases. For example, Logitech"s Options+ app requires Windows 10 1809 and newer.
Still, it would be really surprising for Mozilla to drop support for a part of Windows 10"s market share, considering the company still supports its browser on Windows 7. And before you start mocking users for running unsupported Windows 10 versions, remember that certain old releases, such as 2015 LTSB and 2016 LTSC, are still supported. Windows 10 2015 LTSB is only going away in October 2025, while version 2016 LTSC will keep getting updates until October 2016.
However, as it turned out, Mozilla is not killing Firefox on pre-1803 Windows 10 versions.
Mozilla engineers on Reddit quickly jumped on the matter and confirmed that the problem with Firefox 143 Nightly not running on old Windows 10 versions is just a bug, not an intentional behavior. As such, the issue will likely be fixed in no time. You can track the discovered bug on the official Bugzilla website.
Meanwhile, users created a temporary solution that lets you get the browser working while Firefox software engineers are preparing a permanent fix. This could also be a reminder not to rely on Nightly builds because changes in these releases can sometimes break the browser altogether.
Mozilla has not announced its plans regarding the end of Windows 10 support. However, with Windows 7 still being supported, you can expect developers to continue updating Firefox on Windows 10 for quite a while. Microsoft, on the other hand, recently revealed that the Edge browser will remain supported on Windows 10 for three years after the end of mainstream support in October 2025.