what is the reason for the below error?

The error message indicates that there is a permission that cannot be imported during deployment because one or more of the objects that the permission is associated with already exists in the target database. This means that there may be a conflict between the permissions defined in the source and those already present in the target.

To resolve this issue, you can try one of the following approaches:

1. Modify the permission in the source to match the existing permission in the target database.
2. Remove the conflicting objects from the target database and redeploy.
3. Use a deployment script that includes a conditional statement to check if the permission exists in the target database before attempting to create it.
4. Drop and recreate the target database, if possible, to ensure that it matches the source database.

You may also want to review the deployment plan to identify the specific permission and object that are causing the error and determine the best course of action.