If you have upgraded the Events module and then when viewing the module’s page you are presented with the error: "Argument 'Length' must be greater or equal to zero.", there was a problem with one of the upgrade processes. You can read about it here.

http://www.dotnetnuke.com...dpage/2/Default.aspx

But essentially, to fix it, you paste this code into the host, SQL window and run it as a script. It sets the module up to restart the upgrade process. After you run the script, go to the Host Settings and restart the application. Hopefully that will take care of it.

UPDATE {databaseOwner}{objectQualifier}EventQueue
SET IsComplete = 0,
Attributes = '<Attributes><Attribute><Name>BusinessControllerClass</Name><Value>DotNetNuke.Modules.Events.EventController, DotNetNuke.Modules.Events</Value></Attribute><Attribute><Name>DesktopModuleId</Name><Value>'
+ CONVERT(varchar, DesktopModuleID)
+ '</Value></Attribute><Attribute><Name>UpgradeVersionsList</Name><Value>04.01.00</Value></Attribute></Attributes>'
FROM {databaseOwner}{objectQualifier}EventQueue CROSS JOIN
{databaseOwner}{objectQualifier}DesktopModules
WHERE (EventQueue.EventMessageID IN
(SELECT MAX(EventMessageID) AS Expr1
FROM {databaseOwner}{objectQualifier}EventQueue AS EventQueue_1
WHERE (Attributes LIKE '%DotNetNuke.Modules.Events.EventController, DotNetNuke.Modules.Events%') AND
(ProcessorCommand = N'upgrademodule'))) AND (ModuleName = N'DNN_Events')
GO