Goals

Open RealmSwift 4.4.1 local file with RealmSwift 5.5.0.

Expected Results

When opening RealmSwift 4.4.1 files with RealmSwift 5.5.0 we expect the file to be upgraded and opened without any errors.

Actual Results

RealmSwift 5.5.0 reports a fatal error "Key Already Used" when trying to open a Realm 4.4.1 file.

Steps for others to Reproduce

Open the Realm 4.4.1 file with an app using the Swift 5.5.0 RealmSwift library.

Code Sample

Can provide the Realm 4.4.1 file to debug via private channel

Version of Realm and Tooling

Realm framework version: Original realm file is RealmSwift 4.4.1.
Upgrading to RealmSwift 5.5.0

Realm Object Server version: Realm Cloud (not sure of what version)

Xcode version: 12.1

iOS/OSX version: macOS 10.15.7

Dependency manager + version: N/A