NSKeyedUnarchiver error after renaming Xcode project

another way is to fix the name of the class used for NSCoding. You simply have to use:

• NSKeyedArchiver.setClassName("Record", forClass: Record.self before serializing
• NSKeyedUnarchiver.setClass(Record.self, forClassName: "Record") before deserializing

wherever needed.

Looks like iOS extensions prefix the class name with the extension's name.

Don't change your project name. Just change the display name. It's the "Bundle display name" entry in your Info.plist. You'll probably need to add the entry.

See this answer if you want to change the display name of an OS X app.

In Case if you moved your file to another module, you would need to add additional information

NSKeyedArchiver.setClassName("OldModule.ClassName", for: ClassName.self)
NSKeyedUnarchiver.setClass(ClassName.self, forClassName: "OldModule.ClassName")