Even after uninstalling the message_digest module, I found the error creating the new user ID. So I decided to manually remove traces from the Database configuration field. Now my entire site receives the following error
The website encountered an unexpected error. Please try again later.DrupalCoreFieldFieldException: Attempt to create a field message_digest that does not exist on entity type user. in DrupalfieldEntityFieldConfig->getFieldStorageDefinition() (line 315 of core/modules/field/src/Entity/FieldConfig.php).
Now I cannot install and enable this module to return to normal condition.
I am stuck in this problem. Please help me get rid of this problem.