6x SilverDragon_Overlay/minimap.lua:34: SilverDragon/achievements.lua:625: 'for' limit must be a number
[string "=[C]"]: in function (for generator)' [string "@SilverDragon_Overlay/minimap.lua"]:34: in function RefreshAllData'
[string "@SilverDragon_Overlay/minimap.lua"]:253: in function ?' [string "@Atlas/Libs/CallbackHandler-1.0-8/CallbackHandler-1.0.lua"]:109: in function <...las/Libs/CallbackHandler-1.0/CallbackHandler-1.0.lua:109> [string "=[C]"]: ? [string "@Atlas/Libs/CallbackHandler-1.0-8/CallbackHandler-1.0.lua"]:19: in function <...las/Libs/CallbackHandler-1.0/CallbackHandler-1.0.lua:15> [string "@Atlas/Libs/CallbackHandler-1.0-8/CallbackHandler-1.0.lua"]:54: in function Fire'
[string "@GatherMate2/Libs/HereBeDragons/HereBeDragons-2.0-22.lua"]:300: in function <...GatherMate2/Libs/HereBeDragons/HereBeDragons-2.0.lua:283>
[string "@GatherMate2/Libs/HereBeDragons/HereBeDragons-2.0-22.lua"]:330: in function <...GatherMate2/Libs/HereBeDragons/HereBeDragons-2.0.lua:329>

Locals:
=

A possible fix for this error:
In achievements.lua add a new line after line 611: if ns.CLASSICERA then return end

So this is the original:
611: function ns:LoadAllAchievementMobs()
612: if not _G.GetAchievementInfo then
613: achievements_loaded = true
614: end

This is the modification:
611: function ns:LoadAllAchievementMobs()
612: if ns.CLASSICERA then return end
613: if not _G.GetAchievementInfo then
614: achievements_loaded = true
615: end

I guess the problem here is that Classic Era has no achievements, so any function looking for achievements in Classic Era will eventually error out.