In latest version of MaterialDesign WPF this problem is showing.
Is there any property or something else to hide it?
Code:
<TextBox materialDesign:HintAssist.Hint="First Name" FontSize="18" Style="{StaticResource MaterialDesignFloatingHintTextBox}" MaxLength="50"/>
There is already an issue on GitHub concerning how to hide the character counter.
It is already confirmed that there will be a way to disable it in the upcoming release.
In the next release there will be a new attached property you can use to hide the character counter.
<TextBox MaxLength=""10"" materialDesign:TextFieldAssist.CharacterCounterVisibility=""Collapsed""/>
In the meanwhile you can either downgrade to a previous version of MaterialDesign, as this feature was introduced in version 4.0 or you can use the workaround suggested in the issue.
<TextBox>
<materialDesign:TextFieldAssist.CharacterCounterStyle>
<Style TargetType="TextBlock" />
</materialDesign:TextFieldAssist.CharacterCounterStyle>
</TextBox>