After a workpaper has been reviewed and signed off, you may want to lock it. A locked workpaper is read-only. You cannot upload a new version of a workpaper that is locked. Unlocking a workpaper allows you to make changes to the workpaper.
When a workpaper is locked, the icon displays in the Status column on the Engagement View. The lock status of a workpaper updates automatically for all users as the file is locked or unlocked.
Click in the Actions column for the workpaper, and then select Lock. If this option doesn't display, verify in Engagement View that the file isn't currently in use. When a file is in use, the icon displays in the Status column on the Engagement View. The active user column displays the user name of the person working in the file. The Status column updates automatically as users access and close a file.
Click in the Actions column for the workpaper, and then select Unlock. If this option doesn't display, verify in Engagement View that the file isn't currently in use. When a file is in use, the icon displays in the Status column on the Engagement View. The active user column displays the user name of the person working in the file. The Status column updates automatically as users access and close a file. Active user information is not available for consolidated engagements at this time.
icon displays in the Status column on the Engagement View. The lock status of a workpaper updates automatically for all users as the file is locked or unlocked.
Lock a workpaper
in the Actions column for the workpaper, and then select Lock. 
icon displays in the Status column on the Engagement View. The active user column displays the user name of the person working in the file. The Status column updates automatically as users access and close a file.