Unity 2019.2.18f1: Invalid path when game enters play mode.

I’m getting this error, whenever I hit the play button. I have “Clear on play” enabled on the console, so the message disappears when the game actually entres play mode.

ArgumentException: The specified path is not of a legal form (empty).
System.IO.Path.InsecureGetFullPath (System.String path) (at <567df3e0919241ba98db88bec4c6696f>:0)
System.IO.Path.GetFullPathInternal (System.String path) (at <567df3e0919241ba98db88bec4c6696f>:0)
System.IO.FileInfo.Init (System.String fileName, System.Boolean checkHost) (at <567df3e0919241ba98db88bec4c6696f>:0)
System.IO.FileInfo…ctor (System.String fileName) (at <567df3e0919241ba98db88bec4c6696f>:0)
(wrapper remoting-invoke-with-check) System.IO.FileInfo…ctor(string)
UnityEditor.VisualStudioIntegration.SolutionSynchronizer.ShouldSyncOnReimportedAsset (System.String asset) (at C:/buildslave/unity/build/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs:224)
System.Linq.Enumerable.Any[TSource] (System.Collections.Generic.IEnumerable1[T] source, System.Func2[T,TResult] predicate) (at <351e49e2a5bf4fd6beabb458ce2255f3>:0)
UnityEditor.VisualStudioIntegration.SolutionSynchronizer.SyncIfNeeded (System.Collections.Generic.IEnumerable1[T] affectedFiles, System.Collections.Generic.IEnumerable1[T] reimportedFiles) (at C:/buildslave/unity/build/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs:213)
UnityEditor.SyncVS.PostprocessSyncProject (System.String[ ] importedAssets, System.String[ ] addedAssets, System.String[ ] deletedAssets, System.String[ ] movedAssets, System.String[ ] movedFromAssetPaths) (at C:/buildslave/unity/build/Editor/Mono/SyncProject.cs:165)
UnityEditor.AssetPostprocessingInternal.PostprocessAllAssets (System.String[ ] importedAssets, System.String[ ] addedAssets, System.String[ ] deletedAssets, System.String[ ] movedAssets, System.String[ ] movedFromPathAssets) (at C:/buildslave/unity/build/Editor/Mono/AssetPostprocessor.cs:159)
UnityEditor.SceneManagement.EditorSceneManager:SaveOpenScenes()
AprilGames.Autosave:SaveBeforeRun(PlayModeStateChange) (at Assets/Project/Scripts/Editor/Autosave.cs:23)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) (at C:/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:179)

So I’ve been getting the same (or similar) error with the same first few lines - it appears to go away as soon as I remove vs code in the package manager, but returns as soon as I reinstall it. I’ve updated the unity version, vs code package, completely reinstalled unity, visual studio, and vs code - and the problem is happening on different computers as well. I’m at a loss for how to fix this. Did you ever manage to find a solution?