OWA Has Blank Screen, &reason=0 in the URL After Exchange Update Rollup

This happened on 3 servers after exchange 2010 sp1 update rollup 7. When you go to use OWA it just redirects to a white screen with a long url that ends in &reason=0.

 

1. Go to start, admin tools, IIS.
2. Open the server name, expand sites, expand default website, and expand OWA.
3. Click on the highest version number, which in this case was 14.1.420.0.
4. On the right side, go into the Authentication icon.
5. Disable basic and enable anonymous.
6. Right click anonymous and go to Edit. Make sure the user says IUSR.

 

The changes should be instant but to restart IIS just open cmd elevated and type ‘iisreset’ and press enter.

If it still doesn’t work, go back into the anonymous edit and change the bullet from IUSR to ‘Application pool identity’ to get it working.