You may received the following error: File in use [File Name] is locked for editing by user when creating a letter from the gift record, adding a letter to an action or creating a constituent letter from a constituent record.
Possible causes include:
Microsoft Outlook is running and using Word as its editor
Installing ACT.com software on the workstation, which uses Microsoft Word
Try the following in order until the issue is resolved:
Exit Microsoft Outlook, create and run your letter, re-open Outlook