Drive's viewer is being updated with the new Google Drive. The new viewer is faster, cleaner, and provides easier ways to connect with third-party Drive apps. This version of Drive Viewer also gives viewers a similar experience for Drive content and Gmail attachments.
This change also means that Google will be removing support for file-level commenting of non-Google file formats. Google Docs, Sheets, and Slides will not be impacted and existing comments on non-Google formats will be retained and available to view. We expect to see the new version of Google Drive Viewer in the UMICH domain as the new Google Drive rolls out. For more information, see New Version of Google Drive Viewer.