Product:
Cognos Controller 10.1
Adobe Reader 10

Symptom:
When Cognos Controller user run a standard report, and it show fine in HTML.
Then user change to view it in Adobe Reader PDF format, then they only get a progress bar and the PDF does not show.

Problem:
PDF report does not show – user see a progress bar instead.

Cause:
Adobe Reader 10 is not supported by Cognos Controller 10.1
More information here
http://www-01.ibm.com/support/docview.wss?uid=swg27020782#eft

Solution:
Start Adobe Reader X on the client computer and under menu
edit – preferences
select general dialog
uncheck “Enable Protected Mode at startup”
click OK
Then start Cognos Controller Client, and test a standard report again.

This change is saved per user on the client, so the best is if the IT department can roll out this change of Adobe Reader with a GPO.