Beatmap imports may fail randomly

Describe the bug: osu!lazer likes to throw database errors every once in a while after trying to import all maps from stable. It seems like this issue is thread-based, as it is inconsistent, which means that specifically trying to import the mentioned map will work without throwing any errors.

osu!lazer version: 2019.704.0 / master

Logs:

Could not import (13022 Koji Kondo & Mahito Yokota - Egg Planet)
Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions.
at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ThrowAggregateUpdateConcurrencyException(Int32 commandIndex, Int32 expectedRowsAffected, Int32 rowsAffected)
at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeResultSetWithoutPropagation(Int32 commandIndex, RelationalDataReader reader)
at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.Consume(RelationalDataReader reader)
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.Execute(IRelationalConnection connection)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(DbContext _, ValueTuple`2 parameters)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(IEnumerable`1 commandBatches, IRelationalConnection connection)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(IReadOnlyList`1 entriesToSave)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess)
at Microsoft.EntityFrameworkCore.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess)
at osu.Game.Database.DatabaseWriteUsage.Dispose(Boolean disposing) in G:\Dokumente\GitHub\osu\osu.Game\Database\DatabaseWriteUsage.cs:line 39
at osu.Game.Database.DatabaseWriteUsage.Dispose() in G:\Dokumente\GitHub\osu\osu.Game\Database\DatabaseWriteUsage.cs:line 54
at osu.Game.Database.ArchiveModelManager`2.<>c__DisplayClass28_0.<<Import>b__0>d.MoveNext() in G:\Dokumente\GitHub\osu\osu.Game\Database\ArchiveModelManager.cs:line 323
--- End of stack trace from previous location where exception was thrown ---
at osu.Game.Database.ArchiveModelManager`2.Import(TModel item, ArchiveReader archive, CancellationToken cancellationToken) in G:\Dokumente\GitHub\osu\osu.Game\Database\ArchiveModelManager.cs:line 265
at osu.Game.Database.ArchiveModelManager`2.Import(String path, CancellationToken cancellationToken) in G:\Dokumente\GitHub\osu\osu.Game\Database\ArchiveModelManager.cs:line 172
at osu.Game.Database.ArchiveModelManager`2.<>c__DisplayClass20_0.<<Import>b__0>d.MoveNext() in G:\Dokumente\GitHub\osu\osu.Game\Database\ArchiveModelManager.cs:line 113

I’m getting so many errors and stacktraces it’s hard to distinguish between individual errors. If this seems incomplete I can provide a full log file.

[bdach]

@Akarinnnnn that map imported just fine for me. you may have a locally corrupted database.

[peppy]

Should be resolved with realm.