WPF Textboxes and Textblocks not rendered - wpf

Question

I have a strange behavior of my application on some computers (it only happens at some customer pcs, i can't reproduce it on my machines).
I have an application to enter and view production scrap data. Every column is an control on it's own. The Expanders are accordion Controls from the WPF Toolkit.
Sometimes Textblocks are not visible:
When the bug happens to Textboxes, they are not even consuming any space:
This is the Datatemplate for the Content of the Accordion Item:
<DataTemplate x:Key="YieldAccContent" DataType="Models:Cell">
<DataTemplate.Resources>
<DataTemplate x:Key="It1">
<StackPanel >
<Label BorderBrush="{x:Static SystemColors.ControlLightBrush}" Padding="1" Height="22" BorderThickness="1" Content="{Binding Value}" Visibility="{Binding Cell.CellGroup.ParentMeasurement.IsEnabled, Converter ={StaticResource boolTovisinv}}"/>
<controls:NumberTextbox Text="{Binding Value, Converter ={StaticResource EmptyStringToNullConverter}, UpdateSourceTrigger=PropertyChanged}" Height="22" Width="80" Visibility="{Binding IsEnabledAndBad, Converter ={StaticResource boolTovis}}" Background="AliceBlue">
<i:Interaction.Triggers>
<i:EventTrigger EventName="LostFocus" >
<cmd:EventToCommand Command="{Binding MeasurmentViewModel.LostFocusCommand, Mode=TwoWay, Source={StaticResource Locator}}" PassEventArgsToCommand="True" />
</i:EventTrigger>
</i:Interaction.Triggers>
</controls:NumberTextbox>
<toolkit:MaskedTextBox Mask ="-99999999" Value="{Binding Value, Converter ={StaticResource EmptyStringToNullConverter}, UpdateSourceTrigger=PropertyChanged}" PromptChar=" " Height="22" Width="80" Visibility="{Binding IsEnabledAndGood, Converter ={StaticResource boolTovis}}" IncludeLiterals="True" IncludePrompt="False" Background="AliceBlue" ValueType="{x:Type sys:Int64}" GotFocus="MaskedTextBox_GotFocus_1" SelectionChanged="MaskedTextBox_SelectionChanged_1">
</toolkit:MaskedTextBox>
</StackPanel>
</DataTemplate>
</DataTemplate.Resources>
<StackPanel >
<Label BorderBrush="{x:Static SystemColors.ControlLightBrush}" BorderThickness="1" Padding="1" Height="22" Width="160" Content="{Binding YieldInput}" Background="Moccasin"/>
<Label BorderBrush="{x:Static SystemColors.ControlLightBrush}" BorderThickness="1" Padding="1" Height="22" Width="160" Content="{Binding YieldOutput}" Background="Moccasin"/>
<Label BorderBrush="{x:Static SystemColors.ControlLightBrush}" BorderThickness="1" Padding="1" Height="22" Width="160" Content="{Binding Yield}" Background="Moccasin"/>
<ItemsControl ItemsSource="{Binding Stations}" ItemTemplate="{StaticResource It1}">
</ItemsControl>
</StackPanel>
</DataTemplate>
This is the Accordion Item itself:
<System_Windows_Controls:Accordion ContentTemplate="{StaticResource Cont}" ItemTemplate="{StaticResource Head}" ItemsSource="{Binding Cells}" SelectedIndex="{Binding SelectedAccItem, Mode=TwoWay}" SelectionMode="{Binding MeasurmentViewModel.SelectionMode, Source={StaticResource Locator}}" HorizontalAlignment="Stretch" >
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectedItemsChanged" >
<cmd:EventToCommand Command="{Binding MeasurmentViewModel.SelectedItemsChangedCommand, Mode=TwoWay, Source={StaticResource Locator}}" PassEventArgsToCommand="True" />
</i:EventTrigger>
</i:Interaction.Triggers>
</System_Windows_Controls:Accordion>
What could be the cause of this behavior?

Answer 1

Going by your description about the missing TextBoxes not taking any space, I can only assume that you have a Trigger or Converter attached to their Visibility property. If you put a break point in the Converter that is attached to the offending TextBox, then you can debug whether this is the cause quite easily. I assume that the bool value(s) that you are binding to in the Visibility property is not being set correctly... please check whether this is true.