An ORA-00960:ambiguous column naming in select list error is caused, for example, with the following select statement because the identifier object_name in the order by clause does technically (but not value-wise) identify a column:
select
object_type,
object_name,
obj.*
from
user_objects obj
order by
object_name;
In order to fix this error, at least the identifier object_name of the order by clause must be qualified with the alias:
select
object_type,
object_name,
obj.*
from
user_objects obj
order by
obj.object_name;