diff --git a/manifest.php b/manifest.php
index cb1145e9..d304c6c9 100755
--- a/manifest.php
+++ b/manifest.php
@@ -67,7 +67,6 @@
             MapLtiSectionVisibility::class,
             GenerisSearchWhitelist::class,
             CreateLti1p3RegistrationSnapshotSchema::class,
-            RegisterPortalTheme::class
         ]
     ],
     'update' => Updater::class,
diff --git a/migrations/Version202406060802293772_taoLti.php b/migrations/Version202406060802293772_taoLti.php
index 8666a5dc..3c53073b 100644
--- a/migrations/Version202406060802293772_taoLti.php
+++ b/migrations/Version202406060802293772_taoLti.php
@@ -23,7 +23,7 @@ public function getDescription(): string
 
     public function up(Schema $schema): void
     {
-        $this->runAction(new RegisterPortalTheme());
+        // Action removed due to conflicting with multiple instance implementations.
     }
 
     public function down(Schema $schema): void