Enabling the "Include app-local prerequisites" causes errors or warnings to appear when packaging.
4.17 error:
Packaging (Windows (64-bit)): Program.Main: ERROR: AutomationTool terminated with exception: AutomationTool.AutomationException: Unable to deploy AppLocalDirectory dependencies. No such path: D:\Epic Games\UE_4.17\Engine\Binaries\ThirdParty\AppLocalDependencies\Win64
4.18 and 4.19 binary warning:
WARNING: Unable to deploy AppLocalDirectory dependencies. No such path: D:\Epic Games\UE_4.18\Engine\Binaries\ThirdParty\AppLocalDependencies\Win64
4.18 and 4.19 source error:
Error: System.ArgumentException: Staged filesystem reference cannot reference outside the staging root ({0})
Regression?: No
This occurred in 4.17
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-54448 in the post.