i dont know what exactly this error means.

[shadow.throne]

EsoUI/Ingame/UnitFrames/UnitFrames.lua:1787: attempt to index a nil value
stack traceback:
EsoUI/Ingame/UnitFrames/UnitFrames.lua:1787: in function 'UpdateGroupFramesVisualStyle'
<Locals> constants = [table:1]{RAID_BAR_FONT = "ZoFontGamepad18", RAID_FRAME_OFFSET_Y = 42, GROUP_FRAME_BASE_OFFSET_X = 70, GROUP_FRAME_BASE_OFFSET_Y = 55, GROUP_FRAME_PAD_Y = 9, RAID_FRAME_ANCHOR_CONTAINER_HEIGHT = 504, GROUP_FRAME_PAD_X = 2, GROUP_LEADER_ICON = "EsoUI/Art/UnitFrames/Gamepad/g...", RAID_FRAME_SIZE_Y = 40, RAID_FRAME_SIZE_X = 175, GROUP_FRAMES_PER_COLUMN = 12, RAID_FRAME_OFFSET_X = 179, GROUP_STRIDE = 3, GROUP_FRAME_SIZE_Y = 70, RAID_FRAME_PAD_Y = 2, GROUP_FRAME_OFFSET_X = 162, SHOW_GROUP_LABELS = F, RAID_FRAME_BASE_OFFSET_Y = 50, GROUP_BAR_FONT = "ZoFontGamepad34", RAID_FRAME_BASE_OFFSET_X = 100, GROUP_FRAME_OFFSET_Y = 79, RAID_FRAME_PAD_X = 4, RAID_FRAME_ANCHOR_CONTAINER_WIDTH = 175, NUM_COLUMNS = 2, GROUP_FRAME_SIZE_X = 160}, groupFrame = ud, raidTemplate = "ZO_RaidFrameAnchor_Gamepad_Tem...", groupSize = 2, i = 1, unitTag = "group2", anchor = [table:2]{} </Locals>
EsoUI/Ingame/UnitFrames/UnitFrames.lua:2084: in function 'OnGamepadPreferredModeChanged'
EsoUI/Libraries/ZO_PlatformStyle/ZO_PlatformStyle.lua:45: in function 'ZO_PlatformStyle:Apply'
<Locals> self = [table:3]{} </Locals>
EsoUI/Libraries/ZO_PlatformStyle/ZO_PlatformStyle.lua:20: in function 'ZO_PlatformStyleManager:OnGamepadPreferredModeChanged'
<Locals> self = [table:4]{}, _ = 48, object = [table:3] </Locals>
EsoUI/Libraries/ZO_PlatformStyle/ZO_PlatformStyle.lua:11: in function '(anonymous)'

[Sharlikran]

That is not from a mod so I can't tell you which one. The only way to troubleshoot that is to do this

1. Exit the game
2. Make sure you have Minion installed
3. Right click each mod and choose Reinstall
4. Log into the game
5. Disable all mods

Then only enable one mod at a time until you get the error. Try to narrow it down. There is no way to tell from the error because that's all the default UI.

[Friday_The13_rus]

Are you using a mod that modifies group frames? If it is true, I think that is a bug in ESO code. For some reason, if standard group frames are hidden the mentioned error throws.

I am faced with this issue when I used Bandits UI mod with replaced group frames. The error is happening on switching between gamepad and keyboard.