ConcurrentModificationException, no Mods button

[m.e]

When launching the Minecraft client, I get the ConcurrentModificationException error, and then the Mods button does not appear.

 

20:20:35 FATAL]: Fatal error launching game. Report this to http://bugs.mojang.com please!

java.util.ConcurrentModificationException

 

I used forge-1.8.9-11.15.0.1707-installer.jar to install Forge and minecraft_server.1.8.9.jar and the latest Minecraft.jar download. Java is:

openjdk version "1.8.0_65"

OpenJDK Runtime Environment (build 1.8.0_65-b17)

OpenJDK 64-Bit Server VM (build 25.65-b01, mixed mode)

 

[Choonster]

Upload the FML log (logs/fml-client-latest.log) to Gist and link it here.

[m.e]

That file does not exist. There is only logs/latest.log (for that see https://gist.github.com/martinellison/c08e1e51648e7a6c2709.js, but it doesn't shine any light on the issue). There are also earlier versions of the server log.

[Choonster]

Is this message printed in the launcher log? If so, post that using Gist.

 

When linking a Gist, either copy the URL from the address bar or select Share in the dropdown menu next to the URL textbox and copy that URL. The Embed URL is for embedding the Gist into a webpage.