To reproduce the issue:

ASPX:

<telerik:RadTextBox ID="RadTextBox1" runat="server" MaxLength="1700" TextMode="MultiLine" Height="100px" Width="500px">
</telerik:RadTextBox>



Codebehind:

    protected void Page_Load(object sender, EventArgs e)
    {
        RadTextBox1.Text = @"aaaa aaaa aaaa aaaa aaaa aaaa aaaa bbbb aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa bbbb aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa aaaa ";
    }



Load the page, copy the text bbbb and paste it over some aaaa string. The cursor will go to the end and the contents scrolled to the bottom. See the attached video for more information.



The problem has been initially reported in this forum https://www.telerik.com/forums/ie11-radtextbox and recently in ticket #1153271.

When entering a letter in a DigitsOnly Masked textbox, the cursor is moved to the right instead of staying in the same place. 

Demo https://demos.telerik.com/aspnet-ajax/maskedtextbox/overview/defaultcs.aspx

Edge(wrong) - https://www.screencast.com/t/cYRBNxyKNs

Chrome(expected) - https://www.screencast.com/t/OcAxrVKPuYb8

P.S. when pressing 3 keys at the same time, the cursor goes to the end, it might be relevant to this issue

When setting client events in a RadTextBox and using an EmptyMessage, the EmptyMessage will trigger the event on page load.  This is true for a multiple TextMode but others are untested. 

<telerik:RadMaskedTextBox ID="txtCountryDigits" runat="server" SelectionOnFocus="CaretToBeginning" PromptChar="_" Width="50px" Mask="+###" ValidationExpression="+\d{1}.d{1}.d{1}" MaxLength="4" />
<telerik:RadMaskedTextBox ID="txtPhoneNumber" runat="server" SelectionOnFocus="CaretToBeginning" PromptChar="_" Width="116px" Mask = "(###) ###.####" ValidationExpression = "\(\d{3}\) \d{3}\.\d{4}" />
<telerik:RadMaskedTextBox ID="txtExtension" runat="server"  SelectionOnFocus="CaretToBeginning" PromptChar="_" Width="100px" Mask="x##########" MaxLength="11" />

This only affects the Edge browser as far as I can tell.

The Country Digits and Extension only allow one character to be entered when the MaxLength is set equal to the number of characters in the mask.  You can only enter 1 character if you tab into the control.  Click on the control with the cursor does not allow the entry of any digits.   Removing the MaxLength property allows entry of the full input.

When RadText boxes have EnableAriaSupport=True and also have a tooltip set, the JAWS form fields dialog should list the control along with any text that might be in the textbox.
Currently it does not list the text.
see following support ticket for more details:  https://www.telerik.com/account/support-tickets/view-ticket?threadid=1081024

Date format pattern mapping is incorrect in method InputUtil.MapDateFormatShortCuts:

case "y":
          return dateTimeFormatInfo.MonthDayPattern;
case "Y":
          return dateTimeFormatInfo.MonthDayPattern;

instead of:

case "y":
          return dateTimeFormatInfo.YearMonthPattern;
case "Y":
          return dateTimeFormatInfo.YearMonthPattern;

according to "Standard Date and Time Format Strings" from 
https://msdn.microsoft.com/en-us/library/az4se3k1(v=vs.110).aspx

The PasswordStrengthChecker doesn't update if you right-click and paste using only the mouse.

If multiline textbox has set text that starts with break lines, on every postback one break line disappears form the text.

RadMaskedTextBox has a RequireCompleteText property that makes it a requirement that the full mask of the input be satisfied. The RadInputManager MaskedTextBoxSetting does not contain the same property. Please add this property with the same functionality to the MaskedTextBoxSetting.

When we use the control RadNumericTextBox, we met a issue: right alignment for text works under IE8, but doesn't work under IE 10, still left align in this control.  we tried several methods to try fix this issue, 
<telerik:RadNumericTextBox runat="server" ID="control1" Type="Number" ShowSpinButtons="True" ButtonsPosition="Right" IncrementSettings-Step="10"  NumberFormat-DecimalDigits="0" AutoPostBack="False" CssClass="RightPadding" EnabledStyle-CssClass="RightAligned">
  <DisabledStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <EnabledStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <FocusedStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <ReadOnlyStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <InvalidStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <EmptyMessageStyle HorizontalAlign="Right" CssClass="RightAligned" />
  <HoveredStyle HorizontalAlign="Right" CssClass="RightAligned" />

CSS:
<style type="text/css">
 .RightAligned
  {
    text-align: right !important;
  }

   .RightPadding {
        padding-right:2px !important
   }
</style>

but failed. 

Do you have solution to fix this issue?

Expect your reply!

  <telerik:RadNumericTextBox ID="RadNumericTextBox1" runat="server" 
MinValue="-999" MaxValue="999" NumberFormat-DecimalSeparator=","
    Type="Number" AllowOutOfRangeAutoCorrect="false" DataType="System.Decimal" NumberFormat-DecimalDigits="4"></telerik:RadNumericTextBox>

1) type in "12345,4321"

2) blur and the control give an error. The typed value became: "12345.4321"

3) The comma "," decimal separator is changed into dot "."