Project referencing deleted files won't package

I’m trying to package my project and I’m getting a ton (more than 50, so I can’t see them all) of these:
UATHelper: Packaging (Windows (64-bit)): Cook: LogInit: Display: CookResults: Error: Error loading D:/Unfinished Business/GGJ-2018/UnfinishedBusiness/Content/SoulCity/Environment/Textures/Water/T_Soul_Water01_N.uasset!(edited)
The Content/SoulCity folder was deleted long ago, so none of those files exist.

I’ve tried to Fix Up Redirectors, but it doesn’t seem to do anything.

How do I get these dead references out of my project?

Try to search those files in Windows Explorer and delete it.