Not sure what happened to my first reply, if it got lost in the matrix but here we go again: I've tried using lightweight migrations. I've also tried excluding the migration plan fully from my configuration, that leads to different errors. Either way, I want to do bigger changes to my model in the future and I would like to understand what I'm doing wrong :(

I did try with lightweight migration, if that's what you mean? static let migrateV1toV2 = MigrationStage.lightweight( fromVersion: SchemaV1.self, toVersion: SchemaV2.self ) I've also tried with no migration plan at all, but in the future I need to make bigger changes to my model and therefor need to understand what I'm doing wrong :(