Field mapping Error

Hi,

Trying to map Lead entity filed with Opportunity and getting this below erro.

This field map is invalid. A valid field map must meet these requirements:
- The data type must match.
- The length of the target field cannot be shorter than the source field.
- The format should match.
- The target field must not be used in another mapping.
- The source field must be visible on the entity form.
- The target field must be a field a user can enter data into.
- Address ID values cannot be mapped. If you contact support, please provide the technical details.