Oracle Solution for Error ora-54004

ORA-54004: resultant data type of virtual column is not supported

What triggered the Error:

The data type of the underlying expression is not supported. Only scalar data types are supported for virtual columns. LONG, BLOB, REF, and BFILE data types are not supported for virtual columns.

What should we do to fix it:

Specify the expression of virtual column to return a supported scalar data type.