Error: "The attachment cannot be accessed the file may have been modified outside of Act!" when adding attachments to an Opportunity June 06, 2019 14:21 Symptom: Error: "The attachment cannot be accessed the file may have been modified outside of Act!" when adding attachments to an Opportunity Product Details: Product Family: Act! Product: Act! Premium Version: v18.1 Update 3 Environment: OS: Windows 10 Cause: There is no known cause for this issue. Solution: Close Act! Reopen Act! and test issue Related articles How to attach a document to a Contact, Group, Company, or Opportunity in Act! How to uninstall the Act! Premium (access via web) Outlook Integration Emails sent through Outlook are recieved without formatting and have a "winmail.dat" attachment How do I convert my Word Template to an .adt Template? Can I add a Product field to my Detail View layout in Opportunities?