In the SalesLogix 7.5.3 web client, when you navigate to a main view you might receive an error stating “Object Reference not set to an instance of an object”.  There are many things that might cause this.  If you look in the web server’s event logs, under the Application events you should see an error logged.

Recently, I ran into one such error where the stack trace was something like:

2010-12-30 09:31:19,235 ERROR Global – Unhandled exception. System.Web.HttpUnhandledException: Exception of type ‘System.Web.HttpUnhandledException’ was thrown. —-> System.NullReferenceException: Object reference not set to an instance of an object. at SmartParts_TaskPane_CommonTasks_CommonTasksTasklet.DetermineAdHocStatus() at SmartParts_TaskPane_CommonTasks_CommonTasksTasklet.OnPreRender(EventArgs e) at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)—- End of inner exception stack trace—- at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.role_aspx.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

This error points out the offending area was the CommonTasksTasklet, specifically the method DetermineAdHocStatus().  This method is defined on the CommonTasksTasklet.ascx.cs file which is a custom smart part under SmartParts/Taskpane/CommonTasks.

This method loops through the CurrentGroupConext collection to find the current group and see if it is an ad-hoc group or not.  The only problem is the code does not check to see if the CurrentGroup list context is null.  The code current code looks like:

private void DetermineAdHocStatus()
{
    GroupContext groupContext = GroupContext.GetGroupContext();
    string currentGroupID = groupContext.CurrentGroupID;

    foreach (GroupInfo gi in groupContext.CurrentGroupInfo.GroupsList)
    {
        if (gi.GroupID == currentGroupID)
        {
            if ((gi.IsAdHoc) ?? false)
            { _currentIsAdHoc = true; }
        }
        if ((gi.IsAdHoc) ?? false)
        { _contextHasAdHoc = true; }
        break;
    }
}

It should be something like:

private void DetermineAdHocStatus()
{
    GroupContext groupContext = GroupContext.GetGroupContext();
    string currentGroupID = groupContext.CurrentGroupID;
    if (groupContext != null && groupContext.CurrentGroupInfo != null)
    {
        foreach (GroupInfo gi in groupContext.CurrentGroupInfo.GroupsList)
        {
            if (gi.GroupID == currentGroupID)
            {
                if ((gi.IsAdHoc) ?? false)
                { _currentIsAdHoc = true; }
            }
            if ((gi.IsAdHoc) ?? false)
            { _contextHasAdHoc = true; }
            break;
        }
    }
}

So the code above should prevent the error in the first place, but the real reason for this error is that the main view the user is navigating to does not have a group defined or a group defined released to the user.  When the code tries to loop through the current group collection it errors out because there is no current group collection.