Edited Issue: TextBox with MaskedEditExtender not showing value when the TextBox.Text is set [27312]

Version : 4.1.60919.0 & 4.1.60623.0

I use MaskedEditExtender to format the TextBox input as time format (hh:mm)
When the TextBox.Text is set to time value e.g 10:00 in code behind or in the aspx, the TextBox only display blank time placeholder.

Here are some of the codes :

<asp:TextBox ID="tbCourseStartDate" runat="server" Width="100px" Text="10:00"></asp:TextBox>
<ajaxToolkit:MaskedEditExtender
ID="meeCourseStartDate" runat="server" ClearTextOnInvalid="true" Mask="99:99"
MaskType="Time" TargetControlID="tbCourseStartDate"
UserTimeFormat="TwentyFourHour">
</ajaxToolkit:MaskedEditExtender>
<ajaxToolkit:MaskedEditValidator ID="mevCourseStartDate" runat="server"
ControlToValidate="tbCourseStartDate" ControlExtender="meeCourseStartDate"></ajaxToolkit:MaskedEditValidator>

I also include the script error in the Chrome browser (Inspect element)
It looks like the MaskedEdit.MaskedEditBehavior.js is not complete