forge 1.10 just doesn't start

[Remyria]

the launcher closes, trying to start minecraft, then the crash screen appear with http://pastebin.com/A6HYiNq8 is there a way to fix it?

(neither 1.10.2 recommended and last did work, and I got the exact same error than the 1.10 one, before you tell me "use latest version")

 

EDIT: I thought you would have liked to have the 1.10.2 logs anyway: http://pastebin.com/1nRbJ23F

[Choonster]

[00:38:19] [main/INFO] [sTDERR]: [net.minecraftforge.fml.relauncher.FMLLaunchHandler:setupHome:106]: java.lang.NoClassDefFoundError: cpw/mods/fml/relauncher/IFMLLoadingPlugin

 

You have a coremod for 1.7.10 or earlier installed. If you post the full FML log (logs/fml-client-latest.log), it will say which mod this is.

[Remyria]

hum...aaah, I can't have multiple versions at the same time, I didn't know. I had 1.7.10 mods to play on a private serv with a friend, I removed the 1.7.10 mods and the game started perfectly, thank you

[Choonster]

hum...aaah, I can't have multiple versions at the same time, I didn't know. I had 1.7.10 mods to play on a private serv with a friend, I removed the 1.7.10 mods and the game started perfectly, thank you

 

You can if you tell the launcher to use a separate game directory for each version.

[Remyria]

oh really? can you give me an example of how it would work?

[Choonster]

oh really? can you give me an example of how it would work?

 

In the profile editor: