that's a stored procedure which is expected to exist - the only reason it would not is if you had a failed upgrade (or if you used a 3rd party sql script which dropped it). Typically I would close this and direct you to the forums, but as its easy to fix, here is the script you need (from the 7.2.0 sqldataprovider) - go to host->sql and enter the following:

IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id(N'

{databaseOwner}{objectQualifier}vw_MessagesForDispatch') and OBJECTPROPERTY(id, N'IsView') = 1)
DROP VIEW {databaseOwner} {objectQualifier}vw_MessagesForDispatch
GO

CREATE VIEW {databaseOwner}[{objectQualifier}

vw_MessagesForDispatch]
AS
SELECT CMR.RecipientID
,CMR.MessageID
,CMR.UserID
,CMR.[Read]
,CMR.Archived
,CMR.EmailSent
,CMR.EmailSentDate
,CMR.EmailSchedulerInstance
,CMR.CreatedByUserID
,CMR.CreatedOnDate
,CMR.LastModifiedByUserID
,CMR.LastModifiedOnDate
,CMR.SendToast
,CM.NotificationTypeID
,CASE 
WHEN CM.NotificationTypeID IS NULL
THEN
ISNULL ((SELECT UP.[MessagesEmailFrequency] AS Expr1
FROM

{databaseOwner}{objectQualifier}CoreMessaging_UserPreferences UP
WHERE (UP.UserId = CMR.UserID) AND (UP.PortalId = CM.PortalID)), 0)
ELSE
ISNULL ((SELECT UP.[NotificationsEmailFrequency] AS Expr1
FROM {databaseOwner} {objectQualifier}CoreMessaging_UserPreferences UP
WHERE (UP.UserId = CMR.UserID) AND (UP.PortalId = CM.PortalID)), 2)
END EmailFrequency
FROM {databaseOwner}{objectQualifier}

CoreMessaging_MessageRecipients AS CMR 
INNER JOIN

{databaseOwner} {objectQualifier}

CoreMessaging_Messages AS CM 
ON CMR.MessageID = CM.MessageID
GO

cathal,

Thanks.

I really appreciate what you did 

The script executed successfully, but I still get System.Data.SqlClient.SqlConnection. errors

AssemblyVersion:7.3.3
PortalID:-1
PortalName:
UserID:-1
UserName:
ActiveTabID:-1
ActiveTabName:
RawURL:
AbsoluteURL:
AbsoluteURLReferrer:
UserAgent:
DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke
ExceptionGUID:39431e01-5f0b-4e19-b32a-eb1e5adc7b3a
InnerException:Invalid object name 'dbo.vw_MessagesForDispatch'.
FileName:
FileLineNumber:0
FileColumnNumber:0
Method:System.Data.SqlClient.SqlConnection.
StackTrace:
Message:
System.Data.SqlClient.SqlException (0x80131904): Invalid object name 'dbo.vw_MessagesForDispatch'.
at System.Data.SqlClient.SqlConnection. (SqlException exception, Boolean breakConnection)
at System.Data.SqlClient.SqlInternalConnection. (SqlException exception, Boolean breakConnection)
at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning()
at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
at System.Data.SqlClient.SqlDataReader.ConsumeMetaData()
at System.Data.SqlClient.SqlDataReader.get_MetaData()
at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
at DotNetNuke.Data.PetaPoco.PetaPocoExt.ExecuteReader(Database database, String sql, Object[] args)
at DotNetNuke.Data.PetaPoco.PetaPocoHelper.ExecuteReader(String connectionString, CommandType type, Int32 timeout, String sql, Object[] args)
at DotNetNuke.Data.SqlDataProvider.ExecuteReader(String procedureName, Object[] commandParameters)
at DotNetNuke.Services.Social.Messaging.Data.DataService.GetNextMessagesForInstantDispatch(Guid schedulerInstance, Int32 batchSize)
at DotNetNuke.Services.Social.Messaging.Internal.InternalMessagingControllerImpl.GetNextMessagesForInstantDispatch(Guid schedulerInstance, Int32 batchSize)
at DotNetNuke.Services.Social.Messaging.Scheduler.CoreMessagingScheduler.HandleInstantMessages(Guid schedulerInstance)
at DotNetNuke.Services.Social.Messaging.Scheduler.CoreMessagingScheduler.DoWork()

and:

THREAD ID:5
TYPE:DotNetNuke.Services.Social.Messaging.Scheduler.CoreMessagingScheduler, DotNetNuke
EXCEPTION:Invalid object name 'dbo.vw_MessagesForDispatch'.
RESCHEDULED FOR:27/10/2014 6:33:00 μμ
SOURCE:STARTED_FROM_TIMER
ACTIVE THREADS:0
FREE THREADS:1
READER TIMEOUTS:0
WRITER TIMEOUTS:0
IN PROGRESS:0
IN QUEUE:6
Server Name: rea

not sure, I would guess that your site uses an objectQualifier and that you perhaps ran a script (such as turbosql) that altered core tables and didn't use that objectQualifier - either way this is not an issue we can recreate so please raise it in the forums/exchange area on dnnsoftware.com

Yes, you are right.

Thanks or the support.

I will do that.

Best Regards.