Hello Edward ,
Thank you for contacting us.
I think the problem here comes from the mask you've entered (0.9 Hours). Here "H" represents hour edit and "s" represents seconds edit and between them you will have the string "our". Mu guess is that you should see either something like "0.9 2our43 with this mask, or an exception.
I will be glad to help you with your problem if you send us more information on what you would like to achieve. Exact step by step instructions will also help me to reproduce the error. Feel free to send me your project, if you think it will help me get the erroneous behavior.
I'm looking forward for your reply.
the Telerik team