diff --git a/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
index c37f7840faa2..a06db6072be8 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
@@ -576,7 +576,12 @@ public class CtrlMouseHandler extends AbstractProjectComponent {
         ApplicationManager.getApplication().runReadAction(new Runnable() {
           @Override
           public void run() {
-            fullTextRef.set(provider.generateDoc(anchorElement, originalElement));
+            try {
+              fullTextRef.set(provider.generateDoc(anchorElement, originalElement));
+            }
+            catch (IndexNotReadyException e) {
+              fullTextRef.set("Documentation is not available while indexing is in progress");
+            }
             if (anchorElement instanceof PsiQualifiedNamedElement) {
               qualifiedNameRef.set(((PsiQualifiedNamedElement)anchorElement).getQualifiedName());
             }