Amidst crashed!

[John1999]

[info] Amidst v4.1
[info] Current system time: 2016-07-12 22:06:51.992
[info] System.getProperty("os.name") == 'Windows 7'
[info] System.getProperty("os.version") == '6.1'
[info] System.getProperty("os.arch") == 'x86'
[info] System.getProperty("java.version") == '1.8.0_91'
[info] System.getProperty("java.vendor") == 'Oracle Corporation'
[info] System.getProperty("sun.arch.data.model") == '32'
[info] Not using OpenGL.
[info] Biome profile activated: default
[info] using '.minecraft' directory at: 'C:\Users\Microsoft\AppData\Roaming\.minecraft', libraries: 'C:\Users\Microsoft\AppData\Roaming\.minecraft\libraries'
[info] using biome profiles at: 'biome'
[info] Scanning for profiles.
[info] Successfully loaded profile list.
[info] Beginning latest version list load.
[info] Attempting to download remote version list...
[info] Successfully loaded version list. URL: https://launchermeta.mojang.com/mc/game/version_manifest.json
[info] using minecraft launcher profile 'OptiFine' with versionId '1.9-OptiFine_HD_U_B5'
[info] Loading libraries.
[info] Found library: C:\Users\Microsoft\AppData\Roaming\.minecraft\libraries\optifine\OptiFine\1.9_HD_U_B5\OptiFine-1.9_HD_U_B5.jar
[info] Found library: C:\Users\Microsoft\AppData\Roaming\.minecraft\libraries\net\minecraft\launchwrapper\1.7\launchwrapper-1.7.jar
[crash] Amidst has encounted an uncaught exception on the thread Thread[Thread-4,1,main]
[crash] java.lang.NoClassDefFoundError: io/netty/buffer/ByteBufOutputStream
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Unknown Source)
    at java.lang.Class.getDeclaredFields(Unknown Source)
    at amidst.mojangapi.minecraftinterface.RecognisedVersion.getMainClassFields(RecognisedVersion.java:135)
    at amidst.mojangapi.minecraftinterface.RecognisedVersion.generateMagicString(RecognisedVersion.java:126)
    at amidst.mojangapi.minecraftinterface.RecognisedVersion.from(RecognisedVersion.java:120)
    at amidst.mojangapi.minecraftinterface.local.LocalMinecraftInterfaceBuilder.create(LocalMinecraftInterfaceBuilder.java:34)
    at amidst.mojangapi.file.directory.VersionDirectory.createLocalMinecraftInterface(VersionDirectory.java:106)
    at amidst.mojangapi.MojangApi.set(MojangApi.java:74)
    at amidst.gui.profileselect.LocalProfileComponent.tryLoad(LocalProfileComponent.java:82)
    at amidst.threading.WorkerExecutor.lambda$run$11(WorkerExecutor.java:69)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: io.netty.buffer.ByteBufOutputStream
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 14 more

[CubeTheThird]

Amidst does not work with modded versions of the game, including Optifine.

[stefandollase]

I close this as invalid, because Amidst does not support modded Minecraft.

You can still use Amidst with an unmodded Minecraft profile. To do so, please create a new profile with the Minecraft launcher. Call it something like "Amidst" and use that when Amidst asks you for a profile. Make sure to select the correct Minecraft version when creating the new profile.

For more information, please read the FAQ: Can I use Amidst with a modded Minecraft version?

Optifine might be supported in a future version, see #110