A. Ensure that the app has the necessary permissions to access your contacts. Go to your device's settings, find the app under 'Apps' or 'Applications', and make sure 'Contacts' permission is enabled. If it is already enabled, try disabling and re-enabling it.

B. Clear the app cache and data. Go to Settings > Apps > FNBT & FCB > Storage, then tap on 'Clear Cache' and 'Clear Data'. This can resolve issues related to data corruption.