I recently ran into an issue where my Management Reporter client would hang and crash when exporting or importing building block groups. All other functionality within MR seemed to be working fine. The MR client would hang once I clicked on Import (or Export) and then clicked on the first set of Row Definitions.
The issue ended up being a Microsoft Windows Update that was recently applied to the server. When importing or exporting a building block group MR first brings up a list of Report Definitions. When the cursor is placed over a report name an information balloon is displayed by the MR client. The Windows Update was causing a conflict with this informational balloon causing the application to hang.
A work around for this issue was to import/export building block groups without moving the cursor over the report definition names. When working with the other tabs (Row Definitions, Column Definitions, Reporting Tree Definitions and Dimension Value Sets) you can navigate freely without causing the client to crash.
Microsoft reviewed the issue and confirmed the Windows Update which was causing the issue and will be reviewing the issue. The current release of Management reporter is CU12 so the fix will be included in a later release.
*The fix for the Report Designer crash was included in MR 2012 CU13. For a complete fix list for CU13 visit the documentation here: https://mbs.microsoft.com/files/customer/MgmtReporter/Learning/Documentation/UserGuides/ManagementReporterCU13FixList.pdf