Hi,

It could be that the reports were deleted or are not visible (maybe permissions) from SQL Reporting services (SSRS).

The easiest way to troubleshoot this would be to browse to the SQL Reporting Services site (http://servername/reports) and verify whether the Hidden folder and all the standard reports exist there.

Chances are that they are no longer there.

Run through the configuration manager on the SSRS server to have them reconfigured.

Verify that the K2 service account has "Content Manager" permissions on SSRS and that other domain users have "Browser" rights.

Hope this helps.