Can´t Sign confidential documents

When a document is labeled Confidential with encryption in Microsoft Purview, it becomes RMS protected, meaning the file is encrypted and can only be opened by users with explicit permissions. Because of this, external tools such as DocuSign cannot decrypt or modify the file. DocuSign requires full access to insert signing fields and apply the digital signature, which is not possible on an encrypted document. The only supported approach is to temporarily remove or downgrade the label to a non encrypted version before sending the document for signing. After the customer signs the document, the confidential encrypted label can be reapplied for storage and compliance purposes. Hope this helps!