Sometimes, the format of the email address submitted by a user is not recognized or supported by the Firestore database, or the email address TextField Widget is misconfigured in a project.

Step 1: Verify that the correct TextField Widget is selected as an email address TextField Widget on the page.
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Step 2: Check the format of the email address used.

For instance, a valid email address format is bartholomew@flutterflow.io or xxxxx.xxx@gmail.com or any other format from a service provider.

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