diff --git a/plugin/src/main/java/com/intellij/java/impl/ide/hierarchy/method/OverrideImplementMethodAction.java b/plugin/src/main/java/com/intellij/java/impl/ide/hierarchy/method/OverrideImplementMethodAction.java
index 985c03a40..10233db5f 100644
--- a/plugin/src/main/java/com/intellij/java/impl/ide/hierarchy/method/OverrideImplementMethodAction.java
+++ b/plugin/src/main/java/com/intellij/java/impl/ide/hierarchy/method/OverrideImplementMethodAction.java
@@ -21,6 +21,7 @@
 import com.intellij.java.language.psi.PsiSubstitutor;
 import com.intellij.java.language.psi.PsiSyntheticClass;
 import com.intellij.java.language.psi.util.MethodSignature;
+import consulo.annotation.access.RequiredReadAction;
 import consulo.dataContext.DataContext;
 import consulo.ide.impl.idea.ide.hierarchy.HierarchyNodeDescriptor;
 import consulo.ide.impl.idea.ide.hierarchy.MethodHierarchyBrowserBase;
@@ -95,7 +96,7 @@ public final void actionPerformed(AnActionEvent event) {
                         }
                         else {
                             project.getApplication().invokeLater(
-                                () -> Messages.showErrorDialog(project, status.getReadonlyFilesMessage(), commandName.get())
+                                () -> Messages.showErrorDialog(project, status.getReadonlyFilesMessage().get(), commandName.get())
                             );
                         }
                     }
@@ -157,13 +158,13 @@ else if (canImplementOverride((MethodHierarchyNodeDescriptor) descriptor, method
 
     protected abstract void update(Presentation presentation, int toImplement, int toOverride);
 
+    @RequiredReadAction
     private static boolean canImplementOverride(
         MethodHierarchyNodeDescriptor descriptor,
         MethodHierarchyBrowser methodHierarchyBrowser,
         boolean toImplement
     ) {
-        PsiElement psiElement = descriptor.getPsiClass();
-        if (!(psiElement instanceof PsiClass psiClass)) {
+        if (!(descriptor.getPsiClass() instanceof PsiClass psiClass)) {
             return false;
         }
         if (psiClass instanceof PsiSyntheticClass) {