WowAce

What version of Grid2  are you using (Version is displayed in General/About Tab) ?

 Grid2-beta

What game client version, classic or retail, windows or mac and language are you using ?

 Beta Client

What steps will reproduce the problem?

 Follower Dungeons
Did you try having Grid2 as the only enabled addon and everything else disabled?

No

Was it working in a previous version? If yes, which was the last good one?

5x Grid2/modules/StatusTarget.lua:33: table index is secret
[Grid2/modules/StatusTarget.lua]:33: in function '?'
[LibSharedMedia-3.0-12000001/CallbackHandler-1.0-8/CallbackHandler-1.0.lua]:109: in function <...edia-3.0/CallbackHandler-1.0/CallbackHandler-1.0.lua:109>
[C]: ?
[LibSharedMedia-3.0-12000001/CallbackHandler-1.0-8/CallbackHandler-1.0.lua]:19: in function <...edia-3.0/CallbackHandler-1.0/CallbackHandler-1.0.lua:15>
[LibSharedMedia-3.0-12000001/CallbackHandler-1.0-8/CallbackHandler-1.0.lua]:54: in function 'SendMessage'
[Grid2/GridRoster.lua]:139: in function <Grid2/GridRoster.lua:123>
[Grid2/GridRoster.lua]:176: in function 'RosterRegisterUnit'
[Grid2/GridFrame.lua]:36: in function 'SetFrameUnit'
[Grid2/GridFrame.lua]:88: in function <Grid2/GridFrame.lua:81>
[C]: in function 'SetAttribute'
[Blizzard_RestrictedAddOnEnvironment/SecureGroupHeaders.lua]:210: in function <...rd_RestrictedAddOnEnvironment/SecureGroupHeaders.lua:130>
[Blizzard_RestrictedAddOnEnvironment/SecureGroupHeaders.lua]:495: in function <...rd_RestrictedAddOnEnvironment/SecureGroupHeaders.lua:394>
[C]: in function 'Hide'
[Chat_Sound_Customizer/libs/AceGUI-3.0-41/widgets/AceGUIContainer-Frame.lua]:125: in function 'Hide'
[Chat_Sound_Customizer/libs/AceGUI-3.0-41/widgets/AceGUIContainer-Frame.lua]:21: in function <...er/libs/AceGUI-3.0/widgets/AceGUIContainer-Frame.lua:19>

Locals:
self = <table> {
indicators = <table> {
}
priorities = <table> {
}
dbx = <table> {
}
name = "target"
enabled = true
}
_ = "Grid_UnitUpdated"
unit = "party1"
(*temporary) = <table> {
Vehicle-0-2085-2805-50380-209057-0000709F4D = "party1"
}
(*temporary) = <no value>
(*temporary) = "table index is secret"
guiTarget = <no value>
curTarget = false
roster_units = <table> {
Vehicle-0-2085-2805-50380-209057-0000709F4D = "party1"
}

 I am not sure if this is SharedMedia's fault or not!

I think you are using a old grid2 beta version , Update to version 3.0.7.