When adding weekly timesheet in Netsuite it shows error as below.

Solution
Check the employee record details of employees who can’t enter the timesheet. If he is an inactive employee this error will be populated by the system.
To check this, Navigate to List> Employees> Employees
Check the box show inactive. If the inactive box is checked please remove the tick mark and submit it.

Check the hire date of the employee in the employee record given in the future date. If it is a future date the error will be thrown by the system.
The hire date will be added in the human resource tab of the employee record.
Also, check if you are giving any termination date for the respective employee record. If yes please remove the termination date and save it.

Then enter the time track entry through the weekly timesheet.
You can update the employee record if you have admin access in the production account.