I had an interesting call with a customer today who, since yesterday, could no longer upload attachments to emails using Chrome 60.0.3112.90 m.
When clicking on 'Add Attachment' and selecting a file to upload, a blank error dialog appears:
Worked fine up to yesterday. Works fine in IE11.
By updating to Chrome 60.0.3112.101 m the issue was resolved. Just sharing this in case anyone else has similar with this specific release.