Coredata fetch is crashing with error "Fatal error: NSArray element failed to match the Swift Array Element type"

We have a coredata entity named User with the schema as below -

name String, aliases Transformable

Note: aliases is an String array.

The fetch code is like this -

let request = NSFetchRequest.init(entityName:"User")

userDetails = try self.viewContext.fetch(request) as? [User]

The fetch request is intermittently crashing with the below errors -

Fatal error: NSArray element failed to match the Swift Array Element type

Expected UserProfile but found _NSCoreTypesetterLayoutCache

Fatal error: NSArrav element failed to match the Swift Arrav Element tvpe

Expected NSFetchRequestResult but found NSAsynchronousFetchResult

Please let me know if anyone has any suggestions.