Check if the direct manager or the application administrators can access the timesheet, edit it and add the blank timesheet line back in, save and then cancel the timesheet to ensure that the timesheet does not remain open.
Also, to prevent this you can utilize the workflow step definitions to ensure that project close and cancel steps will also close the work plan and tasks
You can also can use the following workaround to remove that timesheet line from backend via SQL then you shall be able to cancel or save the tm.
a. Make a backup of the tables that we will run delete statement.
b. DELETE FROM TM_ACTUALS_EFFORT WHERE ACTUALS_ID IN (SELECT ACTUALS_ID FROM TM_ACTUALS TA WHERE TA.TIME_SHEET_LINE_ID=); DELETE FROM TM_ACTUALS WHERE TIME_SHEET_LINE_ID=; DELETE FROM TM_LINE_CHARGE_CODES WHERE TIME_SHEET_LINE_ID=; DELETE FROM TM_USERS_TIME_APPROVERS WHERE APPROVER_TIME_SHEET_LINE_ID=; DELETE FROM TM_TIME_SHEET_LINES WHERE TIME_SHEET_LINE_ID=; commit;
You need to replace with the real timesheet line ID that you want to remove.
To figure out ts_line_id, run something like:
select * from tm_time_sheets where description like '%your information here%'
That would give you the ts_id for the timesheet belonging to this description. Then, run
select * from tm_time_sheet_lines where time_sheet_id=
this will give you the time_sheet_line_id linked with this timesheet, and identify the time_sheet_line_id that you need to delete.