What causes "Notifications already resumed" in airbnb/epoxy?

Wrap mutations so resume is only called once per successful pause

airbnb/epoxy · error · IllegalStateException

Notifications already resumed

Error message

Notifications already resumed

What it means

This IllegalStateException is a symmetric state guard in ModelList.resumeNotifications. The class tracks pause/resume of change notifications with a boolean flag; resumeNotifications is only valid when notifications are currently paused. It throws when called while notificationsPaused is false — i.e. resumeNotifications() was called without a prior, still-active pauseNotifications() call (never paused, or already resumed). The source block shows a generic boolean state guard, so the faulting input is the invalid call sequence: a second resumeNotifications() after notifications were already resumed, or a resume with no matching pause. Callers should pair every pauseNotifications()/resumeNotifications() in balanced, non-reentrant blocks (e.g. begin/end or try/finally around batch mutations).

Solutions

Wrap mutations so resume is only called once per successful pause
Track pause state in app code or use a boolean guard before resuming
Avoid calling internal ModelList.resumeNotifications directly
Fix exceptions thrown between pause and resume so the pair stays balanced

Example fix

// before
list.resumeNotifications(); // may throw if not paused
// after
if (paused) {
  list.resumeNotifications();
  paused = false;
}

Defensive patterns

Strategy: try-catch

Try / catch

try { list.resumeNotifications(); } catch (IllegalStateException e) { Log.w(TAG, "not paused", e); }

Prevention

Only resume after a successful pause
Use try/finally so exceptions don't leave the list in a paused state
Track pause state locally before calling resume
Don't call internal APIs from application code

When it happens

Trigger: Calling resumeNotifications() when notificationsPaused is false (never paused, or already resumed).

Common situations: Unbalanced try/finally around list mutations; resuming after an exception already resumed the list; calling internal API from app code.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of airbnb/epoxy@e45bd3a61f (2026-09-13). Data as JSON: /api/errors/45ff2436fd4ca56e. Report an issue: GitHub.

Appendix: source

Thrown at epoxy-adapter/src/main/java/com/airbnb/epoxy/ModelList.java:46

  interface ModelListObserver {
    void onItemRangeInserted(int positionStart, int itemCount);
    void onItemRangeRemoved(int positionStart, int itemCount);
  }

  private boolean notificationsPaused;
  private ModelListObserver observer;

  void pauseNotifications() {
    if (notificationsPaused) {
      throw new IllegalStateException("Notifications already paused");
    }
    notificationsPaused = true;
  }

  void resumeNotifications() {
    if (!notificationsPaused) {
      throw new IllegalStateException("Notifications already resumed");
    }
    notificationsPaused = false;
  }

  void setObserver(ModelListObserver observer) {
    this.observer = observer;
  }

  private void notifyInsertion(int positionStart, int itemCount) {
    if (!notificationsPaused && observer != null) {
      observer.onItemRangeInserted(positionStart, itemCount);
    }
  }

  private void notifyRemoval(int positionStart, int itemCount) {
    if (!notificationsPaused && observer != null) {
      observer.onItemRangeRemoved(positionStart, itemCount);
    }

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