How To Fix UAS012 - Not possible to change column "&1" of type "&2"

UAS012 - Overview

• Message type: E = Error

• Message class: UAS -

• Message number: 012

• Message text: Not possible to change column "&1" of type "&2"

What causes this issue?

You changed the attributes 'key field', 'language-dependent text' or
'posting level' of column &v1& of type &v2&. This change is not possible
because the database tables concerned already contain data and an
automatic conversion of this data is not supported.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

To make the change, you must first delete the existing data for this
type.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

UAS012 - Details

• The SAP error message UAS012, which states "Not possible to change column '&1' of type '&2'," typically occurs when there is an attempt to modify a database table column that is not allowed due to its data type or constraints. Here’s a breakdown of the cause, potential solutions, and related information:
  
  Cause:
  
  Data Type Restrictions: The column you are trying to change may have a data type that does not support the intended modification. For example, you cannot change a column from a numeric type to a character type directly.
  Constraints: The column may have constraints (like primary keys, foreign keys, or unique constraints) that prevent changes.
  Data Integrity: The existing data in the column may not comply with the new data type or constraints you are trying to apply.
  Database Locking: The table might be locked by another transaction, preventing changes.
  
  Solutions:
  
  Check Data Type Compatibility: Ensure that the new data type you are trying to