This is not a new error, I’ve tried this with the GitHub version of UE, when it was 4.7 and the same error was occurring. As I said I’ve reinstalled AndroidWorks and UE. I’ve recently reinstalled my Windows so that won’t be the problem, and this error also occurs on other PCs, not only on mine. I’ve tried to package for ETC1 the same error occurs. If you try it i am 100% sure that you will face the same errors. If you don’t have x64 bit device you can just create a new AVD(Android Virtual Device).