Hi Miki,
I am not sure what be might causing this issue of application getting locked up when Alt+Shift keys are held down. I am not seeing this happening here with TextBoxExt. In any case, if you want any keys to behave as desired, then you may catch the KeyDown event of the TextBoxExt and handle the keys you want.
void textBoxExt1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Alt && e.Shift)
{
Console.WriteLine("ALT+SHIFT combination keys held down");
e.Handled = true;
}
}
Here is a sample for your reference
http://websamples.syncfusion.com/samples/Tools.Windows/F69150/main.htmPlease update us a sample with more details on this that would help us to resolve the problem at the earliest.
Thanks for using Syncfusion Products.
Regards,
Rajagopal