Unityのエラーの意味と解決法がわかりません

Question

前提・実現したいこと

発生したエラーの意味と解決法を知りたい

発生している問題・エラーメッセージ

UnityException: Parse can only be called from the main thread.
Constructors and field initializers will be executed from the loading thread when loading a scene.
Don't use this function in the constructor or field initializers, instead move initialization code to the Awake or Start function.
UnityEngine.Hash128.Parse (System.String hashString) (at <480508088aee40cab70818ff164a29d5>:0)
Unity.QuickSearch.SearchIndexer.Read (System.IO.Stream stream, System.Boolean checkVersionOnly) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchIndexer.cs:594)
Unity.QuickSearch.SearchIndexer.ReadIndexFromDisk (System.String indexFilePath, System.Boolean checkVersionOnly) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchIndexer.cs:1251)
Unity.QuickSearch.SearchDatabase.CombineIndexes (Unity.QuickSearch.SearchDatabase+Settings settings, Unity.QuickSearch.SearchDatabase+IndexArtifact[] artifacts, Unity.QuickSearch.SearchTask`1[T] task) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchDatabase.cs:421)
Unity.QuickSearch.SearchDatabase+<>c__DisplayClass45_0.<ResolveArtifacts>b__0 () (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchDatabase.cs:386)
Unity.QuickSearch.SearchTask`1+<>c__DisplayClass34_0[T].<RunThread>b__0 () (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchTask.cs:99)
System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Threading.ThreadHelper.ThreadStart () (at <437ba245d8404784b9fbab9b439ac908>:0)
UnityEngine.Hash128:Parse(String)
Unity.QuickSearch.SearchIndexer:Read(Stream, Boolean) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchIndexer.cs:594)
Unity.QuickSearch.SearchIndexer:ReadIndexFromDisk(String, Boolean) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchIndexer.cs:1251)
Unity.QuickSearch.SearchDatabase:CombineIndexes(Settings, IndexArtifact[], SearchTask`1) (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchDatabase.cs:421)
Unity.QuickSearch.<>c__DisplayClass45_0:<ResolveArtifacts>b__0() (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchDatabase.cs:386)
Unity.QuickSearch.<>c__DisplayClass34_0:<RunThread>b__0() (at Library/PackageCache/com.unity.quicksearch@2.1.0-preview.1/Editor/Indexing/SearchTask.cs:99)
System.Threading.ThreadHelper:ThreadStart()

Answer 1

UnityException: Parse can only be called from the main thread.

Parse はメインスレッドからしか呼べない、という意味です。

Unity の Quick Search というパッケージが出しているようなので、使っていないようなら Package Manager から削除すればよいです。使っているなら、まずは preview 版ではなく、正式リリース版（現時点での最新は 2.0.2）を使いましょう。