We had the same error in our project (sometimes during cooking, somethins in the Gather_Text commandlet).
After diffing the UE5 code, I think this got fixed in CL18437695 (or https://github.com/EpicGames/UnrealEngine/commit/6695703481dadbb21ea9b64ba5d4065489831934 in case you are using GIT) by Epic. It seems to not be anywhere in the 4.26 or even 4.27 branch.
But if you are compiling the engine from source, porting it back should be kindof easy enough (some functions got shuffled around, but are easy enough to find in the 4.26 branch… also, if you compile with VS2017, you need to fix some compile errors about auto-template-deduction…)