Adding and removing mods

[AlexDeathwind]

So I have a server that is just me, my wife and a couple of friends and we want EE2 over EE3.Now I know how to delete EE3, but will every have to delete it in their mod folder and if I add EE2 will they have to add it?

 

[AlexDeathwind]

Bump, Also this is for FTB Ultimate and when I just manually swap the two the server crashes on starttup.

 

[Tsugaga]

Add it in your mods folder, then at the ftb launcher main screen, select "edit pack" or w/e, and put the EE2 mod into your client mod pack.

 

[AlexDeathwind]

When I do that I get this error

10:36:39 AM
CONSOLE:
[SEVERE] Encountered an unexpected exception LoaderException
10:36:39 AM
CONSOLE:
java.lang.NoSuchMethodError: ic2.api.Items.getItem(Ljava/lang/StringLur;