This is likely a compatibility issue with the latest EUI beta: since BuildInstance is never used by Firaxis for any other purpose than a subroutine to GetInstance, it was not included in EUI's optimized instance manager (which overwrites InstanceManager.lua).
In the next EUI version I will add a dummy BuildInstance function (that does nothing) to improve compatibility... In the mean time, you can safely delete line 402 from Sukritact's Events and Decisions (v 3)\Lua/UI/EnactDescisionsPopup.lua.
Edit:
Actually with the base game InstanceManager, the mod's BuildInstance call on line 402 of EnactDescisionsPopup.lua defeats the action of its ResetInstances call line 323, so the mod will spam new hidden instances and eventually cause an out of memory crash. If the goal was to make the sure the instances appeared in a predictable order, the mod should be using GenerationalInstanceManager:new instead of InstanceManager:new, but in no case should it use BuildInstance. CityInfoStack.lua and RandomEventsPopup.lua both have the same issue. Proposed fix attached (untested).
Given my analysis this mod needs a fix, I will not be making any change to EUI.