Hi Chris,

Thank you for reporting this issue! I’ve reproduced it and converted the ticket into a public bug report so that other users experiencing the same problem will be notified.

In the meantime, please try one of the following workarounds:

• Switch the spellchecker provided to EditDistance: SpellCheckProvider="EditDistanceProvider"
• If you prefer to keep using the default spell check provider, you can patch the client-side script. Save the following code in a file (e.g., scripts.js) and load it via the DialogsScriptFile="scripts.js"
  
  ASPX
  

  <telerik:RadTextBox ID="RadTextBox1" Text="tha" runat="server"></telerik:RadTextBox>
  <telerik:RadSpell DialogsScriptFile="scripts.js" ID="RadSpell1" runat="server" ControlsToCheck="RadTextBox1"></telerik:RadSpell>

  
  script.js
  

      Telerik.Web.UI.SpellCheckService.prototype._processResponse = function(executor, args) {
                  var statusCode = executor.get_statusCode();
  
                  if (executor.get_responseAvailable() && 200 == statusCode && executor.get_responseData().length > 0) {
                      var result = executor.get_object();
      alert(1)
      if (result.badWords != null) {
                          var jsonCompatible = result.badWords;
      jsonCompatible = jsonCompatible.replace(/([{,]\s*)([a-zA-Z0-9_]+)\s*:/g, '$1"$2":');
      jsonCompatible = jsonCompatible.replace(/'((?:\\.|[^\\'])*)'/g, '"$1"');
      jsonCompatible = jsonCompatible.replace(/\\'/g, "");
  
      result.badWords = JSON.parse(jsonCompatible);
                      }
  
      if (result.wordOffsets != null) {result.wordOffsets = JSON.parse(result.wordOffsets); }
  
      this.raise_complete(executor.get_object());
                  } else {
                      if (executor.get_timedOut()) {
          alert('Spell Check Request time out');
                      } else if (executor.get_aborted()) {
          alert('Spell Check Request aborted');
                      } else if (404 == statusCode) {
          window.alert('Web.config registration missing!\n The spellchecking functionality requires a HttpHandler registration in web.config. Please, use the control Smart Tag to add the handler automatically, or see the help for more information.\n\n' + this.get_url());
                      } else if (statusCode > 0 && statusCode != 200) {
          window.alert('Spell Check Handler Server Error:' + statusCode + '\n' + executor.get_responseData());
                      }
                  }
              }
  

As a small token of gratitude for your contribution, your Telerik points have been updated. We appreciate your help in improving our product!

Regards,
Rumen
Progress Telerik