Some image prevent note from upload, and sync button show error.
Try create note and insert this image to content. If convert this image then no issue.
I uploaded image to dropbox to be sure it's not changed.
https://www.dropbox.com/s/oa97hi57pm53804/evernote-sync-error.png?dl=0
macOS Siera 10.12.6
Version 7.11 (457846 Direct)
Editor: 69.1.8237 (1f0aea9)