DerivedDataKey exception

I’ve made a transient texture and saved it to the game package, however the process doesn’t seem to be complete somehow. I had previously thought that this was the result of missing mip maps, but after figuring out how to add them the problem hasn’t been resolved.

Exception thrown at 0x000007FEE26D4274 (UE4Editor-Engine.dll) in UE4Editor.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

	if (AsyncTask)
		delete AsyncTask;
		AsyncTask = NULL;

So this error happens on shutdown of the editor after creating and saving the texture. If I open or use the texture without shutting down it works fine.

Then, if I do use the texture or save it then reload, I get this exception:

Assertion failed: RunningPlatformData->DerivedDataKey == DerivedDataKey [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.8\Engine\Source\Runtime\Engine\Private\TextureDerivedData.cpp] [Line: 1711] 

check( RunningPlatformData->DerivedDataKey == DerivedDataKey );

Under what circumstances are the derived data keys created? The first error makes it look like the texture is gone from memory, but it’s obviously not completely done with the save process. Also, side question: how do you add breakpoints to the engine? They just seem to get ignored. Do I need to recompile the engine each time I add a breakpoint? It’s making it impossible to see how UE does things like this itself. Also interesting, I don’t have a D:\ drive…