SQL Error: ORA-00913: too many values

You should specify column names as below. It’s good practice and probably solve your problem

insert into abc.employees (col1,col2) 
select col1,col2 from employees where employee_id=100; 

EDIT:

As you said employees has 112 columns (sic!) try to run below select to compare both tables’ columns

select * 
from ALL_TAB_COLUMNS ATC1
left join ALL_TAB_COLUMNS ATC2 on ATC1.COLUMN_NAME = ATC1.COLUMN_NAME 
                               and  ATC1.owner = UPPER('2nd owner')
where ATC1.owner = UPPER('abc')
and ATC2.COLUMN_NAME is null
AND ATC1.TABLE_NAME = 'employees'

and than you should upgrade your tables to have the same structure.