Make the Attachment Field Read-onlySummaryTo set Attachment field type to read only in UIInstructionsSetting read-only via UI policy won't work for field of type File Attachment.The only way to make attachment field on form non editable is by creating individual field level WRITE ACL on that field.Related LinksDocumentation for ACL Creation From the Vancouver release, the file attachment field type can now be set to read-only via UI Policy due to the fix applied in PRB1502915.