This is the first official release after ExtremeLauncher v3, unfortunately, old versions of ExtremeLauncher (v2 and v3) started breaking really badly and Java support was not all that great.
We recommend all users update to v4 as soon as possible.
ExtremeLauncher v4 is now fully compatible with Java 16, Java 17, etc. which fixes some of the issues users were experiencing with Minecraft 1.17 and above.
ExtremeLauncher 4.0.0.2 fixes the issues where versions.json would not be downloaded appropriately, causing the launcher to crash.
ExtremeLauncher 4.0.0.3 update was released in order to address some security and performance issues, instead of external libraries ExtremeLauncher now uses native Windows Zip functions, .NET Framework was updated to 4.7.2 as .NET Framework 4.6.1 reached the end of support.
ExtremeLauncher 4.0.0.4 fixes downloading process for older versions of Minecraft.
ExtremeLauncher 4.0.0.5 will attempt to auto-redownload corrupted files from Minecraft servers.
ExtremeLauncher 4.0.0.6, improved internet connectivity detection.
ExtremeLauncher 4.0.0.7, stable release, public.