UI Error at startup

[gboeer]

Since today i get those errors at game startup. MM doesn't seem to do anything afterwards ... any suggestions what I could do?

user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:455: operator .. is not supported for string .. nil
stack traceback:
user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:455: in function 'MMScrollList:SetupSalesRow'
user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:968: in function 'setupCallback'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2511: in function 'ZO_ScrollList_UpdateScroll'
/EsoUI/Libraries/ZO_Templates/ScrollTemplates.lua:2267: in function 'ZO_ScrollList_Commit'
/EsoUI/Libraries/ZO_SortFilterList/ZO_SortFilterList.lua:160: in function 'ZO_SortFilterList:CommitScrollList'
/EsoUI/Libraries/ZO_SortFilterList/ZO_SortFilterList.lua:143: in function 'ZO_SortFilterList:RefreshData'
user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:985: in function 'MMScrollList:InitializeDataType'
user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:990: in function 'MMScrollList:New'
user:/AddOns/MasterMerchant/MasterMerchant_UI.lua:3766: in function 'MasterMerchant:SetupScrollLists'
user:/AddOns/MasterMerchant/MasterMerchant.lua:2965: in function 'MasterMerchant:InitScrollLists'
user:/AddOns/MasterMerchant/MasterMerchant.lua:2937: in function 'Queue'
user:/AddOns/MasterMerchant/Libs/LibExecutionQueue/LibExecutionQueue.lua:34: in function 'lib:executeNextTask'
user:/AddOns/MasterMerchant/Libs/LibExecutionQueue/LibExecutionQueue.lua:35: in function 'func'
/EsoUI/Libraries/Globals/globalapi.lua:263: in function '(anonymous)'