Latest version, haven't seen it before.

2x SavedInstances\SavedInstances-8.0.9.lua:3875: attempt to index field '?' (a nil value)
SavedInstances\SavedInstances-8.0.9.lua:3875: in function `ShowTooltip'
SavedInstances\SavedInstances-8.0.9.lua:2427: in function <SavedInstances\SavedInstances.lua:2425>
Titan\LDBToTitan.lua:327: in function <Titan\LDBToTitan.lua:286>

Locals:
self =

{
SetDefaultModuleLibraries = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:398
localarr#categoryrow = {
}
lastrefreshlock = 431778.486000
EnableModule = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:363
HeaderFont = defined @SavedInstances\SavedInstances.lua:3325
CancelTimer = defined @datastore\libs\AceTimer-3.0\AceTimer-3.0.lua:147
RequestLockInfo = defined @SavedInstances\SavedInstances.lua:2522
localarr#blankrow = {
}
TRADE_SKILL_LIST_UPDATE = defined @SavedInstances\SavedInstances.lua:4376
SetDefaultModulePrototype = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:440
defaultModuleState = true
EncounterEnd = defined @SavedInstances\SavedInstances.lua:2625
localarr#columns = {
}
ScheduleTimer = defined @datastore\libs\AceTimer-3.0\AceTimer-3.0.lua:94
DisableModule = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:381
ADDON_LOADED = defined @SavedInstances\SavedInstances.lua:2502
RegisterMessage = defined @datastore\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:90
UnregisterMessage = defined @datastore\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:153
RegisterBucketEvent = defined @SavedInstances\Libs\AceBucket-3.0\AceBucket-3.0.lua:184
memcheck = defined @SavedInstances\SavedInstances.lua:2868
scan_item_cds = defined @SavedInstances\SavedInstances.lua:4269
localarr#showcol = {
}
SetEnabledState = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:455
enabledState = true
RegisterEvent = defined @datastore\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:90
localarr#RefreshTemp = {
}
IterateModules = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:468
TradeSkillRescan = defined @SavedInstances\SavedInstances.lua:4355
CHAT_MSG_MONSTER_YELL = defined @SavedInstances\SavedInstances.lua:2593
localarr#wbsave = {
}
OnInitialize = defined @SavedInstances\SavedInstances.lua:2351
NewModule = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:266
GetModule = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:241
ShowTooltip = defined @SavedInstances\SavedInstances.lua:3337
defaultModuleLibraries = {
}
TimeLeft = defined @datastore\libs\AceTimer-3.0\AceTimer-3.0.lua:172
SendMessage = defined @datastore\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:59
ScheduleRepeatingTimer = defined @datastore\libs\AceTimer-3.0\AceTimer-3.0.lua:129
CancelAllTimers = defined @datastore\libs\AceTimer-3.0\AceTimer-3.0.lua:160
toonInit = defined @SavedInstances\SavedInstances.lua:2335
localarr#instancerow = {
}
GetName = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:310
QuestRefresh = defined @SavedInstances\SavedInstances.lua:2880
localarr#lfrbox = {
}
localarr#instancesaved = {
}
name = "SavedInstances_Core"
localarr#categoryshown = {
}
RegisterBucketMessage = defined @SavedInstances\Libs\AceBucket-3.0\AceBucket-3.0.lua:200
orderedModules = {
}
scale = 1
Disable = defined @accountant\Libs\AceAddon-3.0\AceAddon-3.0.lua:345
Enable = defined @Accoun

Yes, it's happening every time on every toon. Basically as soon as my cursor hits the key icon the error occurs.