Unable to attach Microsoft Project (mpp) files to ProjectsIssue Microsoft Project (mpp) files cannot be attached to Projects. The same issue occurs when attaching mpp files to other tables, such as Tasks or Incidents. Release Cause The instance blocks uploads and attachments for file types that are not MIME types. The mpp file extension is not a MIME type, so the system blocks mpp file attachments to Projects. Resolution 1. Open the system property glide.security.mime_type.aliasset. 2. Append the following value, comma separated, to the end of the existing value: application/vnd.ms-project=application/x-tika-msoffice 3. Save the property. This allows mpp files to be attached to Projects. Related Links Unable to import mpp files into SPM for Project - KB2821250