upgrade to 2021.2

ProjectSettings/PackageManagerSettings.asset

@@ -12,10 +12,11 @@ MonoBehaviour:
   m_Script: {fileID: 13964, guid: 0000000000000000e000000000000000, type: 0}
   m_Name: 
   m_EditorClassIdentifier: 
-  m_EnablePreviewPackages: 1
+  m_EnablePreReleasePackages: 0
   m_EnablePackageDependencies: 0
   m_AdvancedSettingsExpanded: 1
   m_ScopedRegistriesSettingsExpanded: 1
+  m_SeeAllPackageVersions: 0
   oneTimeWarningShown: 1
   m_Registries:
   - m_Id: main
@@ -27,17 +28,8 @@ MonoBehaviour:
   m_UserSelectedRegistryName: 
   m_UserAddingNewScopedRegistry: 0
   m_RegistryInfoDraft:
-    m_ErrorMessage: 
-    m_Original:
-      m_Id: 
-      m_Name: 
-      m_Url: 
-      m_Scopes: []
-      m_IsDefault: 0
-      m_Capabilities: 0
     m_Modified: 0
-    m_Name: 
-    m_Url: 
-    m_Scopes:
-    - 
-    m_SelectedScopeIndex: 0
+    m_ErrorMessage: 
+    m_UserModificationsInstanceId: -824
+    m_OriginalInstanceId: -826
+  m_LoadAssets: 0