Keep the app open and connected to Wi‑Fi or a stable network
Plug the device into power
Disable Low Power Mode or battery saver
Make sure the app has permission to access Messages, Contacts, Photos, and Files if needed
Restart the device
Force close and reopen the app
Update the app to the latest version
Update the device software to the latest version
Check that enough storage space is available
Leave the device idle for a while so indexing can complete
Turn Messages sync off and back on if using cloud sync
Sign out and sign back in to the account if indexing is stuck
Rebuild or reindex the message database if the app provides that option
Delete and reinstall the app if the issue persists
Contact app support if indexing still does not finish