Looks like [UE-94675][1] is still present in 4.26.1:
[2021.02.04-03.59.43:858][ 0]LogOutputDevice: Error: === Handled ensure: ===
[2021.02.04-03.59.43:858][ 0]LogOutputDevice: Error:
[2021.02.04-03.59.43:859][ 0]LogOutputDevice: Error: Ensure condition failed: FMemory::Memcmp(ActualData, OverrideValue.GetBytes(), Key.GetSizeInBytes()) == 0 [File:D:/Build/++UE4/Sync/Engine/Plugins/FX/Niagara/Source/Niagara/Private/NiagaraComponent.cpp] [Line: 2535]
[2021.02.04-03.59.43:859][ 0]LogOutputDevice: Error:
[2021.02.04-03.59.43:860][ 0]LogOutputDevice: Error: Stack:
[2021.02.04-03.59.43:860][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd25ef3d10 UE4Editor-Niagara.dll!UnknownFunction []
[2021.02.04-03.59.43:860][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd25acf516 UE4Editor-Niagara.dll!UnknownFunction []
[2021.02.04-03.59.43:860][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd25b26b97 UE4Editor-Niagara.dll!UnknownFunction []
[2021.02.04-03.59.43:861][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd25b0ae4c UE4Editor-Niagara.dll!UnknownFunction []
[2021.02.04-03.59.43:861][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42cea27d UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:862][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e08948 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:862][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42df97b7 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:862][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e19222 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:863][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e17f30 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:863][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e28faf UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:864][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e33f45 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:864][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd42e335d8 UE4Editor-CoreUObject.dll!UnknownFunction []
[2021.02.04-03.59.43:864][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd248bc6df UE4Editor-DataValidation.dll!UnknownFunction []
[2021.02.04-03.59.43:865][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd248bd2d4 UE4Editor-DataValidation.dll!UnknownFunction []
[2021.02.04-03.59.43:865][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd248c53df UE4Editor-DataValidation.dll!UnknownFunction []
[2021.02.04-03.59.43:865][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd248c65f3 UE4Editor-DataValidation.dll!UnknownFunction []
[2021.02.04-03.59.43:866][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd248be297 UE4Editor-DataValidation.dll!UnknownFunction []
[2021.02.04-03.59.43:866][ 0]LogOutputDevice: Error: [Callstack] 0x00007ff6963499e9 UE4Editor-Cmd.exe!UnknownFunction []
[2021.02.04-03.59.43:867][ 0]LogOutputDevice: Error: [Callstack] 0x00007ff696340eac UE4Editor-Cmd.exe!UnknownFunction []
[2021.02.04-03.59.43:867][ 0]LogOutputDevice: Error: [Callstack] 0x00007ff69634121a UE4Editor-Cmd.exe!UnknownFunction []
[2021.02.04-03.59.43:868][ 0]LogOutputDevice: Error: [Callstack] 0x00007ff69635527d UE4Editor-Cmd.exe!UnknownFunction []
[2021.02.04-03.59.43:868][ 0]LogOutputDevice: Error: [Callstack] 0x00007ff69635732e UE4Editor-Cmd.exe!UnknownFunction []
[2021.02.04-03.59.43:869][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd917e7c24 KERNEL32.DLL!UnknownFunction []
[2021.02.04-03.59.43:869][ 0]LogOutputDevice: Error: [Callstack] 0x00007ffd9378cea1 ntdll.dll!UnknownFunction []
