Hello! I see you're having trouble making a mobile deposit, and you're receiving an error code 4100. Let's work through this together.

The 4100 error typically indicates an "Invalid FIAcctID," which generally means that there’s an issue with the account ID that’s linked to your mobile app. Here's what we can do to troubleshoot this issue:

### Step-by-Step Solutions:

1. Check Account Status: Make sure your bank account is active and in good standing. If there are any holds or restrictions, that could lead to this error.

2. Log Out and Back In: Sometimes, simply logging out of the Regions mobile app and then logging back in can refresh your session and resolve temporary issues.

3. Update the App: Ensure your Regions mobile app is updated to the latest version. Go to the Google Play Store, search for the Regions app, and see if there's an update available.

4. Clear App Cache:
- Go to Settings on your device.
- Select Apps.
- Find and tap on Regions App.
- Tap on Storage and then Clear Cache.

5. Check Internet Connection: Ensure you have a strong internet connection, as connectivity issues can sometimes lead to errors in app functionality.

6. Reinstall the App: If the above steps do not resolve the issue, you may want to delete the app and reinstall it. This can help reset any corrupted files.

7. Contact Support: If none of these steps work, it may be best to reach out to Regions' customer support directly. You can contact them at [email protected]. They may need to investigate the account settings on their end.

Would you like me to help with any specific step, or do you have any further questions about this issue?