I've tried to send a test a few times, but nothing happens. I've restarted Chrome, and also cleared the cache and rebooted. Is there a site-wide issue? I'm just trying to figure out why it isn't working. I've tried around 10 a.m., and now, 12:45 p.m.
Thanks for doing a great job with those initial troubleshooting steps, that's enabled me to cross a few things off straight away. The problem here lies towards the bottom of your "#AFAAM Special Events & Spirit of Giving" mailing with the "Read > Lead > Achieve" link. To be more specific using the greater-than (>) symbols in a hyperlink confuses the editor and the proofer because they are looking for the remaining HTML which would normally be associated with these symbols.
Normally it would be as simple as just removing the symbols from the mailing, but I can see that they're a part of the logo you're linking to, and so we don't want to remove them completely. The best workaround here is to go into the editor and carefully highlight just the ">" symbols, select "remove link," then just add an underline and change the color to make them look like they're a part of the link. This will allow you keep your link uniform without actually including those greater-than symbols in the link itself, whilst maintaining those three action words as a functional link.
Hope this helps! Please don't hesitate to ask me any follow-up questions here.