Hi lc343765828,
Can you create a page by the code below and test on your site? Does it get the same issue?
<%@ Page Language="C#" %>
<%@ Register TagPrefix="CE" Namespace="CuteEditor" Assembly="CuteEditor" %>
<html>
<head>
<title>example</title>
</head>
<body>
<form id="Form1" runat="server">
<CE:Editor ID="Editor1" runat="server">
</CE:Editor>
</form>
</body>
</html>
Can you delete folder "CuteSoft_Client" and re-deploy it again?
Keep me posted,
Regards,
Ken