Workaround InvalidOperation exceptions

osu.Game/Beatmaps/BeatmapManager.cs

@@ -174,6 +174,22 @@ namespace osu.Game.Beatmaps
             if (beatmapSet.Beatmaps.Any(b => b.BaseDifficulty == null))
                 throw new InvalidOperationException($"Cannot import {nameof(BeatmapInfo)} with null {nameof(BeatmapInfo.BaseDifficulty)}.");
 
+            var dbContext = ContextFactory.Get();
+
+            // Workaround System.InvalidOperationException
+            // The instance of entity type 'RulesetInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+            foreach (var beatmap in beatmapSet.Beatmaps)
+            {
+                beatmap.Ruleset = dbContext.RulesetInfo.Find(beatmap.RulesetID);
+            }
+
+            // Workaround System.InvalidOperationException
+            // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+            foreach (var file in beatmapSet.Files)
+            {
+                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
+            }
+
             // check if a set already exists with the same online id, delete if it does.
             if (beatmapSet.OnlineBeatmapSetID != null)
             {

osu.Game/Database/ArchiveModelManager.cs

@@ -462,6 +462,10 @@ namespace osu.Game.Database
                 // Dereference the existing file info, since the file model will be removed.
                 if (file.FileInfo != null)
                 {
+                    // Workaround System.InvalidOperationException
+                    // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+                    file.FileInfo = usage.Context.FileInfo.Find(file.FileInfoID);
+
                     Files.Dereference(file.FileInfo);
 
                     // This shouldn't be required, but here for safety in case the provided TModel is not being change tracked
@@ -635,10 +639,12 @@ namespace osu.Game.Database
             {
                 using (Stream s = reader.GetStream(file))
                 {
+                    var fileInfo = files.Add(s);
                     fileInfos.Add(new TFileModel
                     {
                         Filename = file.Substring(prefix.Length).ToStandardisedPath(),
-                        FileInfo = files.Add(s)
+                        FileInfo = fileInfo,
+                        FileInfoID = fileInfo.ID
                     });
                 }
             }

osu.Game/Skinning/SkinManager.cs

@@ -142,6 +142,18 @@ namespace osu.Game.Skinning
             }
         }
 
+        protected override void PreImport(SkinInfo model)
+        {
+            var dbContext = ContextFactory.Get();
+
+            // Workaround System.InvalidOperationException
+            // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+            foreach (var file in model.Files)
+            {
+                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
+            }
+        }
+
         /// <summary>
         /// Retrieve a <see cref="Skin"/> instance for the provided <see cref="SkinInfo"/>
         /// </summary>