We are deploying Office Web Apps for Lync.  We can browse the discovery directory from the Front End Server. We get the following 41033 error. Note that the URL is missing.

The Office Webapps Server shows a status of Healthy.

We tried:

-Removing from the topology and adding back

-Removing HTTPS and just using HTTP to rule out the certificate

-Reinstalling the Web Apps farm

Office Web Apps Server (WAC) discovery failed, PowerPoint content is disabled.

Attempted Office Web Apps Server discovery Url:
Received error message: Invalid Uri syntax for WAC configuration
The number of retries: 1, since 4/24/2015 5:00:21 PM.
Cause: Office Web Apps Server may be unavailable or network connectivity may have been compromised.
Resolution:
Check HTTPS connectivity from this box to the Office Web Apps Server deployment using the discovery Url.

So as you state, 41033 means that discovery failed. I'd start by double checking that your WAC is configured correctly in the Lync topology, that the FQDN matches up and that your certificates are all good.

If you browse to https://wacfqdn.domain.com/hosting/discovery do you have any errors? Or do you get XML appear in the browser?

Tripple checked the URLs in the topology and the web apps farm config.  Removed and re-added to the topology as well.

Browsing to the /hosting/discovery URL I see the XML code and there are no errors about the certificate. I also tried it as http to rule out a problem with the certificate.

I think it's odd in the error that the URL is missing. In most examples I found of this error on the web, you usually see the problem URL in the message.

Hi,did you publish topology after WAC farm was setup?

Try enable-cscomputer to see if you get any error.

Please run the following command on your WAC server:

Get-OfficeWebAppsFarm

THen post result here.