To resolve the issue of receiving "Invalid Email and password" messages when trying to log into your FlashAlert App, follow these steps:

1. Verify Email and Password: Ensure that you are using the correct email and password associated with your FlashAlert account. The email you used to sign up is your username. Double-check for any typos or incorrect capitalization.

2. Reset Password: If you cannot remember your password or suspect it might be incorrect, use the password reset feature. Navigate to the login screen, click on "Reset your Password," and follow the instructions to receive a password reset email. Make sure to check your spam folder if you do not see the email in your inbox - learn more.

3. Clear App Cache or Data: Sometimes, clearing the app's cache or data can resolve issues related to login errors. Go to your device's settings, find the FlashAlert App, and clear cache/data before trying to log in again.

4. Reinstall the App: If issues persist, uninstall the FlashAlert App and then reinstall it. This can fix problems caused by corrupted app data. After reinstalling, log in with your email and password.

5. Check for Account Lockout: If you've attempted to log in multiple times with incorrect credentials, your account may temporarily lock you out. Wait for a short period, then attempt to log in again.

6. Contact Support: If you still cannot log in after trying the above steps, you might want to reach out to FlashAlert support. They can assist with account-specific issues or verify your login credentials - learn more.

7. Double Check Network Connection: Ensure your internet connection is stable since connectivity issues might affect logging in. Try switching between Wi-Fi and mobile data to see if that resolves the issue.

By following these steps, you should be able to troubleshoot and solve the login issues with your FlashAlert App.