This article can assist with problems regarding signing into Yahoo! Messenger with an iPhone.

The symptoms may include being looped back to the original sign-in prompt or encountering a sign-in error preventing access to your account.

Additionally, you may be unable to sign in to Yahoo! Messenger on a desktop or laptop computer.

First, try the resolutions suggested in the help page about Troubleshooting the Yahoo! Messenger for iPhone app.

Note: You will not be able to reset the application if you are unable to sign in to Yahoo! Messenger for iPhone.

As a workaround, please try signing in to Yahoo! Messenger in Mail from a desktop computer.

If you are still unable to sign in with your mobile device, please contact us using the Contact Yahoo! button in the lower-right corner.

For the quickest possible resolution, please provide the following details:

1. The exact steps you are taking to sign in. Please indicate if you are using your mobile Web browser or if you are using an official Yahoo! Messenger application on your device.
2. Please provide the exact steps you're following and describe what happens on your screen. Please list the exact text of any error messages that may come up.
3. Note if you are able to sign in with Yahoo! Messenger for Mail.