addEventHandler("onResourceStart", resourceRoot, 
function() 
DonatorsTeam = createTeam ( "Clan Name", 0, 0, 0 ) 
end) 
  
function setDonatorsTeam(player) 
       local accName = getAccountName ( getPlayerAccount ( player ) ) 
        if isObjectInACLGroup ( "user." .. accName, aclGetGroup ( "GroupName" ) ) then 
   setPlayerTeam(player, DonatorsTeam) 
   end 
end 
addEventHandler("onPlayerLogin",getRootElement(),setDonatorsTeam) 
addEventHandler("onPlayerSpawn",getRootElement(),setDonatorsTeam) 
You're code is wrong change the player to source the player is not defined.