I'm only running two man teams right now so I'm not sure what happens if you have more than that but with just two characters If you do /ema-team invite and the other team member is set to offline you get this error.

1x EMA\Core\Team-Team.lua:1226: Usage: C_PartyInfo.InviteUnit(targetName)
[string "=[C]"]: in function InviteUnit' [string "@EMA\Core\Team-Team.lua"]:1226: in function ?'
[string "@arkinventory\Externals\Ace3\AceTimer\AceTimer-3.0-17.lua"]:55: in function <...rkInventory\Externals\Ace3\AceTimer\AceTimer-3.0.lua:50>

Locals:
(*temporary) = nil

The solution is obviously /ema-team setallonline and then do the invite but I just thought I'd let you know this happens :)