diff --git a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
index 4c23676..21f411c 100644
--- a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
+++ b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerSubmitRule.java
@@ -34,6 +34,7 @@
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import java.nio.file.InvalidPathException;
 import java.util.Optional;
 
 /** Submit rule that checks that all files in a change have been approved by their code owners. */
@@ -99,6 +100,11 @@
                 " for patch set %d of change %d",
                 changeData.currentPatchSet().id().get(), changeData.change().getId().get());
       }
+      Optional<InvalidPathException> invalidPathException =
+          CodeOwnersExceptionHook.getInvalidPathException(t);
+      if (invalidPathException.isPresent()) {
+        errorMessage += String.format(" (cause: %s)", invalidPathException.get().getMessage());
+      }
       errorMessage += ".";
       logger.atSevere().withCause(t).log(errorMessage);
       return Optional.of(ruleError(errorMessage));
diff --git a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnersExceptionHook.java b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnersExceptionHook.java
index 8a2e85e..9f07ea2 100644
--- a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnersExceptionHook.java
+++ b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnersExceptionHook.java
@@ -89,7 +89,7 @@
     return getInvalidPathException(throwable).isPresent();
   }
 
-  private static Optional<InvalidPathException> getInvalidPathException(Throwable throwable) {
+  public static Optional<InvalidPathException> getInvalidPathException(Throwable throwable) {
     return getInvalidPluginConfigurationCause(InvalidPathException.class, throwable);
   }