What is this error of packaging

All source files in module “CustomGravityPlugin” must include the same precompiled header first.
Currently “C:\Program Files (x86)\Epic Games\gm\Plugins\CustomGravityPlugin\Source\CustomGravityPlugin\Private\CustomGravityPluginPrivatePCH.h” is included by most of the source files. The following source files are not including “C:\Program Files (x86)\Epic Games\gm\Plugins\CustomGravityPlugin\Source\CustomGravityPlugin\Private\CustomGravityPluginPrivatePCH.h” as their first include: gm C:\Program Files (x86)\Epic Games\gm\Intermediate\ProjectFiles\UnrealBuildTool

please give me some advices.