- Check the file extension of the attachment to identify if it is an allowed file type on your device.
- Ensure that the correct application is installed on your device to open the file format of the attachment.
- Make sure that the app or program associated with the attachment is up to date. It may not open if it is an outdated version.
- Check the file size of the attachment as it may be too large for your device to open.
- Confirm that the attachment downloaded properly; attachments with incomplete downloads may not open.
- Ensure that you have the sufficient permissions or access rights to open the attachment.