if this was a 64 bit registry problem, you wouldn't even get the blank report...
When you describe not being able to select a snapshot for the report, perhaps you need to complete the following procedure: (excerpt from IM r12.5 SP7 Bookshelf)
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Administration Guide › Reporting › How to Run Snapshot Reports› Associate a Snapshot Definition with a Report Task
Associate a Snapshot Definition with a Report Task
Assign a snapshot definition to a report task so CA Identity Manager knows which snapshot definition to use when running the report. Also, information for Identity Manager reports can come from multiple sources, and each report should be associated with a specific data source, depending on the information you want to view in the report.
To associate a snapshot definition and connection with a report task
In the User Console, go to Roles and Tasks, Admin Tasks, Modify Admin Task.
Search for the report task you want to associate a snapshot definition with.
Go to the Tabs tab and click the next to the Associate Snapshot Definitions tab.
Click Add.
Search for the snapshot definition to associate with the report task and click Select.
When associating a snapshot definition with a report task, note the following:
A report can be associated with one or more snapshot definitions.
A snapshot definition can be associated with more than one report.
Multiple snapshots associated with a single report task must not use the same recurrence time.
Click Ok.
Go to the Search tab and click Browse to locate the search screens.
Edit the search screen for the report task and choose rptParamConn under Connection Object for the Report.
Click Ok.
Click Select.
Click Submit.
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PLEASE NOTE: This is a KNOWN ISSUE and a previous version of IM SPX did have a blank roles report... Please make sure you're using the latest version of IM and that you have re-imported the biar file to the report server to take advantage of the fix.
Please respond with any questions or concerns.
Thank you.
Regards,
Chris Thomas
CA Technologies
Principal Support Engineer
Identity Manager Reporting Expert
Tel: +1-631-342-4360
Chris.Thomas@ca.com