I had a search for this error and only came up with this thread which does not help me on this instance, although as my application will be multi user the delegate snippet will be useful to test.

http://mindfusion.org/cgi/Forum/YaBB.pl?action=search2

However, following on from the grouping by locations I find I have another problem.

I have two calendars, one in month view and the other in time table view.

calmonth is linked to caltime so every time a user amends caltime the highlighting is updated accordingly on calmonth.

All works great except when I change location I get the error listed in thread subject on this code:

  For Each s In Me.calMonthView.DayStyles

			  Me.calMonthView.DayStyles.Remove(s)

 Next
 

This code is used in a different place in response to users deleting and appintment and is in an if statement which tests the day/time and removes is required and works ok.

I have not restricted to a day/time as it needs to clear the entire style so that when moving from one location to the other the previous locations styles are cleared before the new locations styles are drawn.

I hope I make sense?

Thanks

Is this something specific to Planner.NET?  I thought if I cycled thru the collection it would only process those that were found in it?

However when I try it this way:

 For x = 0 To Me.calMonthView.DayStyles.Count - 1

	 Me.calMonthView.DayStyles.RemoveAt(x)

 Next
 

I do not get the error which is good but the highlight does not get removed?

OK I have now tracked it down to this bit of code!

The RemoveAt works a treat, however the code below redraws the highlight.

Me.calTimeTableView.LoadFromDataSource()

' clear the calendar locations

Me.calTimeTableView.Locations.Clear()

' add the location chosen by user on form

Me.calTimeTableView.Locations.Add(Me.calTimeTableView.Schedule.Locations(intBuilding))

' and set calendar to group by location

Me.calTimeTableView.GroupType = GroupType.GroupByLocations

' cycle through timetableview items in order to update monthview highlighting

For Each itemMonth In Me.calTimeTableView.Schedule.Items

    ' for every item in the timetableview process it into the monthview

	ProcessItemCreated(itemMonth)

 Next
 

So my confusion is this...

If I have grouped by location and the user has selected location 2 why does the code above process all locations 1 and 2?

I can see I am obviuosly not graspng the full functionality of the Planner control!

Yep, I was on to that before I came back to read your post 

Here is the working result:

 For Each itemMonth In Me.calTimeTableView.Schedule.Items

   Select Case intBuilding

	Case 0

	     If itemMonth.Location.Name = "WHSE1" Then

			   ProcessItemCreated(itemMonth)

	     End If

	 Case 1

		If itemMonth.Location.Name = "WHSE2" Then

			   ProcessItemCreated(itemMonth)

		End If

	  End Select

Next