updated to event 3.3.7.  When adding event to a newly created calendar, received the following error msg:

Error: Edit Event is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: INSERT statement conflicted with COLUMN FOREIGN KEY constraint 'FK_Events_Modules'. The conflict occurred in database 'PPLM_Intranet_BAK', table 'Modules', column 'ModuleID'. The statement has been terminated. ---> System.Data.SqlClient.SqlException: INSERT statement conflicted with COLUMN FOREIGN KEY constraint 'FK_Events_Modules'. The conflict occurred in database 'PPLM_Intranet_BAK', table 'Modules', column 'ModuleID'. The statement has been terminated. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) 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.ExecuteReader(CommandBehavior behavior) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, String commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String connectionString, String spName, Object[] parameterValues) at DotNetNuke.Modules.Events.Data.SqlDataProvider.EventsSave(Int32 PortalID, Int32 EventID, Int32 ModuleID, DateTime EventDateBegin, DateTime EventDateEnd, DateTime EventTimeBegin, Int32 Duration, String EventName, String EventDesc, Int32 Importance, String CreatedBy, String CreatorID, Int32 Every, String Period, String RepeatType, String Notify, Boolean Approved, Boolean Signups, Int32 MaxEnrollment, String EnrollRoleID, Double EnrollFee, String EnrollType, String PayPalAccount, String PayPalPassword, Boolean Cancelled, String ImageURL, String ImageType, Int32 ImageWidth, Int32 ImageHeight, Boolean ImageDisplay, Int32 Location, String LocationName, String MapURL, Int32 Category, String CategoryName, String Color, String Reminder, Int32 TimezoneOffset, Boolean SendReminder, Int32 ReminderTime, String ReminderTimeMeasurement, String ReminderFrom, Boolean SearchSubmitted) at DotNetNuke.Modules.Events.EventController.EventsSave(EventInfo objEvent) at DotNetNuke.Modules.Events.EditEvents.updateButton_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---

Anyone has an idea what may be the cause?