What causes "Library name is not specified" in JetBrains/intellij-community?

Select the unnamed library entry (the dialog navigates to it automatically via navigate()) and type a name

JetBrains/intellij-community · error · ConfigurationException

library.name.is.not.specified

library.name.is.not.specified

Error message

Library name is not specified

What it means

Thrown from BaseLibrariesConfigurable.checkCanApply() when a library entry in Project Structure > Libraries has an empty display name. Every project-level library needs a unique non-empty name so it can be referenced from module dependencies and stored in .idea/libraries. Before this message, a generic empty/duplicate-name check runs; this specific error fires per-configurable for an unnamed library.

Source

Thrown at java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/projectRoot/BaseLibrariesConfigurable.java:90

  }

  @Override
  public boolean isModified() {
    boolean isModified = false;
    for (final LibrariesModifiableModel provider : myContext.myLevel2Providers.values()) {
      isModified |= provider.isChanged();
    }
    return isModified || super.isModified();
  }

  @Override
  public void checkCanApply() throws ConfigurationException {
    super.checkCanApply();
    checkForEmptyAndDuplicatedNames(JavaUiBundle.message("configurable.library.prefix"), CommonBundle.getErrorTitle(), LibraryConfigurable.class);
    for (LibraryConfigurable configurable : getLibraryConfigurables()) {
      if (configurable.getDisplayName().isEmpty()) {
        ((LibraryProjectStructureElement)configurable.getProjectStructureElement()).navigate();
        throw new ConfigurationException(JavaUiBundle.message("library.name.is.not.specified"));
      }
    }
  }

  @Override
  public void reset() {
    super.reset();
    myTree.setRootVisible(false);
  }

  @Override
  protected void loadTree() {
    createLibrariesNode(myContext.createModifiableModelProvider(myLevel));
  }

  @Override
  protected @NotNull Collection<? extends ProjectStructureElement> getProjectStructureElements() {
    final List<ProjectStructureElement> result = new ArrayList<>();

View on GitHub (pinned to be881553f2)

Solutions

Select the unnamed library entry (the dialog navigates to it automatically via navigate()) and type a name
Use a name unique among all libraries in the project to also pass the duplicate-name check that runs before this one

Defensive patterns

Strategy: validation

Validate before calling

for (LibraryConfigurable c : getLibraryConfigurables()) {
  if (c.getDisplayName().isEmpty()) {
    // block apply, focus this library's name field
  }
}

Try / catch

try { configurable.checkCanApply(); } catch (ConfigurationException e) { /* navigate() already focused the unnamed library */ }

Prevention

Name libraries immediately upon creation
Use naming conventions like 'lib:guava-33' to keep names unique and non-empty

When it happens

Trigger: Creating a new library in Project Structure > Libraries and pressing OK without typing a name; renaming an existing library to the empty string.

Common situations: Users adding a library from JARs quickly and forgetting the name field; copy-paste of library definitions clearing names; UI focus issues where the typed name is lost.

Related errors

AI-assisted analysis of JetBrains/intellij-community@be881553f2 (2026-08-14). Data as JSON: /api/errors/375ccf42333fc535. Report an issue: GitHub.