When loading the columns from a file the columns are read in the order they are found in the Columns collection of RadGridView upon saving them.
Setting the DisplayIndex triggers the internal grid logic that ensures the DisplayIndex of each column is correct. 
The combination of the above two operations can cause the grid to invalidate the DisplayIndex of columns while deserializing them and thus setting invalid values.
To ensure correct behaviour when deserializing sort the columns by their display order property before returning them in ProvideValue()

 

This is reproduced when the RadGridView is bound to a ListCollectionView and it is grouped. In such a case, when an item is edited, it is brought to the bottom of the group.

When navigating through the cells with the left/right arrow keys, when the last column is reached normally the focus stays on that cell. However, when there are invisible columns on the left/right of the last visible one, the focus moves away from the grid.

As a workaround you can handle the PreviewKeyDown event of the RadGridView when the CurrentColumn is the last visible one.

When the ItemsSource of the RadGridView is reset, disctinct values remain checked in the Filtering Popup. 

For a workaround, check the attached project. 

When the bound to the RadGridView objects implement the IDataErrorInfo interface and an invalid cell is scrolled out of the viewport, the corresponding row becomes valid.

Columns are not automatically generated when binding to an empty table passed by RadEntityFrameworkDataSource

In multiple selection mode, the GridViewMutiColumnComboBox column does not respect its DisplayMemberPath property.

Users reported that the Text Search feature is misbehaving for certain columns in their grid.

We found that that if we take the Telerik example “DeferredSearching_WPF.sln", and change the "int" field+property to "long" , text search for a number indeed falls over.

Can you reproduce this?

Kind regards, Bertus Distributie ICT

The following exception is observed in certain cases:

at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.FlatLayoutStrategy.RealizeMergedCells(Double frozenOffset, IEnumerable`1 mergedCells)

at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.FlatLayoutStrategy.CalculateMergedCells(Boolean shouldInvalidateMeasure)

at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.CalculateMergedCells(Boolean shouldInvalidateMeasure)

at Telerik.Windows.Controls.GridView.GridViewCellsPanel.ArrangeOverride(Size finalSize)

When two columns in two separate column groups have the same name and they belong two separate column groups, the column group names of the parent column groups can be appended to the display content of the GridViewGroupPanelCells.

For example, the duplicate Code columns in the attached image should have content "PG Code" and "VENUE Code" respectively.

 

The built-in export capabilities for the RadGridView are clunky and not well though out. Additionally, it doesn't fully support exporting hierarchical child data. (You can do it, but you have to go through a good bit of song and dance for something that I've seen other tool sets do automatically.)

I'd like to see the option fully baked that doesn't require code-behind (allowing an MVVM approach). And asynchronous methods that uses standard async-await conventions.

Nested property definitions are visible in situations when they don't match the filtering criteria.

Add a property to the RadGridView that provides a distinct template for adding a new row.

Sometimes you have classes with no default constructor. Those classes may have properties that are read-only after construction. This cannot be handled in the RadGridView, because you only have the choice of a CellEditTemplate. (I'm envisioning something akin to the RowDetailsTemplate.)

Example: I have a class that defines a invoice match for payment application. Once the invoice is set it cannot be changed. The user can still edit the match, but they're only allowed to edit the amount to be applied.

When the RadGridView is bound to a collection of DynamicObject and runtime we add a new property to the objects, this new property will not be respected. The columns will not be refresh.

If your data contains uint, long or any numeric type different than Int32 or Decimal, the searching doesn't work.

The content of the cell is set from .LoadContent() method and is returned from the CreateCellElement method of the column. 

One possible scenario for a fix is to change that behavior and apply directly the template as WPF DataGrid does. However, this is a huge breaking change with CreateCellElement method is widely used. The second approach is to leave the code as it is right now, return the element from method of DataTemplate and set the ContentTemplate property of the cell to that DataTemplate. This will cause the content to be loaded twice. Which will degrade the  

So, as it turns out the solution is either to introduce breaking change or degrade the performance. Both of them are against our believes and efforts to improve the controls. 

Our suggestion is to use a workaround -  setting triggers directly to the style. We do hope you understand our concerns.