This is my project but I don't know how to fix this error

UATHelper: Packaging (Windows (64-bit)): LogInit: Display: CookResults: Error: Error loading D:/Project/Theway/Content/ThirdPersonBP/FirstTerrain_Mat.uasset!
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogCook: Error: Error loading D:/Project/Theway/Content/ThirdPersonBP/FirstTerrain_Mat.uasset!
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: CookResults: Error: Error loading D:/Project/Theway/Content/Level1_BuiltData.uasset!
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LogCook: Error: Error loading D:/Project/Theway/Content/Level1_BuiltData.uasset!

The error message isn’t very descriptive so it’s hard to tell what’s going on.
Do the files that are mentioned exist?

I cannot load this arrest