I have run into an issue with a runtime error when trying to edit a textbox in a datagrid.

"EditItem Not allowed for this view" I think this means that somewhere along the lines it has lost the connection back to the object but I am not sure.

Code:
private ObservableCollection<Model.TextureProperties> AllTextureProperties; 
        public ObservableCollection<Model.TextureProperties> _allTextureproperties
        {
            get{ return AllTextureProperties;}
            set{ AllTextureProperties=value;
                OnPropertyChanged("_allTextureProperties");
            }
        }

        public CourseAssetListViewModel(CourseRepository courseRepository)
        {
            if (courseRepository == null)
            {
                throw new ArgumentNullException("courseRepository");
            }
            _courseRepository = courseRepository;
            
            this.AllTextureProperties = new ObservableCollection<Model.TextureProperties>(_courseRepository.GetTextureProperties());
            //this.Textures = (ListCollectionView) CollectionViewSource.GetDefaultView(this.AllTextureProperties);
            //Textures.Filter
            this.Textures = new CollectionViewSource();
            this.Textures.Source = (from z in this.AllTextureProperties select z.TextureName);

            this.SubTextures = new CollectionViewSource();
            this.SubTextures.Source = (from j in this.AllTextureProperties select j);
        }
Then I have a comboBox as follows
Code:
<ComboBox Name="subtextureselection" HorizontalAlignment="Stretch"  ItemsSource="{Binding Textures.View}"   IsEditable="False" Height="23"  IsSynchronizedWithCurrentItem="True"  Width="123">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel DataContext="{Binding}">

                            <TextBlock Text="{Binding}"/>

                        </StackPanel>
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>
And a DataGrid

Code:
<DockPanel Grid.Row="2" Height="84" HorizontalAlignment="Stretch" Name="dockPanel4" VerticalAlignment="Stretch" >

            <DataGrid ItemsSource="{Binding SubTextures.View}" IsSynchronizedWithCurrentItem="True" >
                
                <DataGrid.Columns>
                    <DataGridTextColumn Header="Lie Angular"   Binding="{Binding Path=LieAngular}" />
                    <DataGridTextColumn Header="Lie Snap Angular"   Binding="{Binding Path=LieSnapAngular}"/>
                    <DataGridTextColumn Header="Lie Power"   Binding="{Binding Path=LiePower}"/>
                    <DataGridTextColumn Header="Lie Snap Power"   Binding="{Binding Path=LieSnapPower}"/>
                    <DataGridTextColumn Header="Restitution"   Binding="{Binding Path=Restitution}"/>
                    <DataGridTextColumn Header="Friction"   Binding="{Binding Path=Friction}"/>
                    <DataGridTextColumn Header="Viscosity"   Binding="{Binding Path=Viscosity}"/>
                    <DataGridTextColumn Header="Maleability"   Binding="{Binding Path=Maleability}"/>
                    <DataGridTextColumn Header="Roll Friction"   Binding="{Binding Path=RollFriction}"/>
                    <DataGridTextColumn Header="Roll Threshold"   Binding="{Binding Path=RollThreshold}"/>
                    <DataGridTextColumn Header="Impact Offset"   Binding="{Binding Path=ImpactOffset}"/>
                    <DataGridTextColumn Header="Angle Miss"   Binding="{Binding Path=AngleMiss}"/>
                    <DataGridTextColumn Header="Power Miss"   Binding="{Binding Path=PowerMiss}"/>
                    <DataGridTextColumn Header="Snap"   Binding="{Binding Path=Snap}"/>
                </DataGrid.Columns>
                
            </DataGrid>
           
        </DockPanel>
The comboBox displays a list of textures and on selection the datagrid populates with a new set of texture values, however as soon as I try to edit any of them in the textbox I get this crash. Can anyone see what I am doing wrong?

Thanks