We were facing issues with OAB in TEST environment , it was not downloading --> on troubleshooting we found some issue that I will discuss in this Blog post.
1. Check Autodiscover via Outlook
2. Just select Auto-discover
3. From XML Tab we found the url of OAB, On opening that URL in browser below was the error received.
The requested page cannot be accessed because the related configuration data for the page is invalid
Now the Resolution:
We found that there was redirection configuration on Default website for OWA, first we had removed that.
Second, We Added Read/Execute permissions for Authenticated users to OAB directory on CAS servers.
This has resolve the issue in our setup.