I just upgraded to EventSentry v2.9x, and when I try to view the web reports I receive the following error: Invalid object name '<TableName>'.

You are receiving this error message because the EventSentry database was not updated to 2.9x and is missing some of the required tables and/or additional columns.

You will need to run the "Database Setup Wizard" in order to update the database, so that the web reports work correctly and the remote agents can write to the database. The "Database Setup Wizard" can be found in Start -> Programs -> EventSentry > Database.