Server Error: Problem Loading webpart - sharepoint

Question

I am trying to add OneViewCalendarWebpart to my site. I am getting the following error when I try to add the webpart from the gallery.
Server Error in '/' Application.
Value cannot be null.
Parameter name: g
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: g
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[ArgumentNullException: Value cannot be null.
Parameter name: g]
System.Guid..ctor(String g) +7452814
Microsoft.GroupBoard.WebControls.CalendarViewControlTraverser.GetListFromCalendarControl() +62
Microsoft.GroupBoard.WebControls.CalendarViewControlTraverser.get_IsSRList() +8
Microsoft.GroupBoard.WebControls.GbwListDeterminer.OnInit(EventArgs e) +83
System.Web.UI.Control.InitRecursive(Control namingContainer) +333
System.Web.UI.Control.InitRecursive(Control namingContainer) +210
System.Web.UI.Control.AddedControl(Control control, Int32 index) +198
System.Web.UI.ControlCollection.Add(Control child) +80
Microsoft.SharePoint.WebControls.SPCalendarView.CreateChildControls() +644
System.Web.UI.Control.EnsureChildControls() +87
System.Web.UI.Control.PreRenderRecursiveInternal() +44
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.WebControls.WebParts.WebPart.PreRenderRecursiveInternal() +42
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Control.PreRenderRecursiveInternal() +171
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842

Answer 1

It seems like the ListName property is not initialized, but the webpart tries to read it (as far as I understand, you are having a problem with Microsoft GroupBoard Workspace webpart).
As far as I can recall from the time I played with the "GroupBoard" solution, these webparts have to be added from code and cannot be added from Webpart gallery. Take a look at the comments in this blog post: http://www.spelements.com/blog/2009/01/printing-sharepoint-lists-calendars/