DOC_NUM is defined as not null and hence the error ORA-01400: cannot insert NULL into ("mac"."ora_cfc"."DOC_NUM")

ORA-01461: can bind a LONG value only for insert into a LONG column occurs when you're trying to insert or update a LONG datatype value into a column that is not defined as LONG

The version field in source is decimal and on Oracle is number.

Check if any of the Decimal fields on the Source is null and you are trying to insert into Oracle number fields which are not null