Troubleshooting
- 3 minutes to read
This section describes common issues and steps you can follow to diagnose and resolve these issues. If the solutions listed here do not help, create a ticket in our Support Center.
To diagnose and collect a detailed information about the issue, see the instructions listed in the following topicS:
- Get Started (How to collect detailed information about the issue)
- KB Article: How to enable script debugging
- KB Article: How to determine the cause of an internal server error
- How to inspect CSS rules
Client-Side Issues
- The ‘X is undefined’ error occurs or extensions are rendered with incorrect styles
- Cannot access DevExpress ASP.NET MVC extensions on the client
- DevExpress MVC extensions do not work after the first callback
- The ‘ReferenceError: ‘X’ is not defined’ error message appears when the Control.Enabled property is set to false
Server-Side Issues
- The controller for ASPxUploadProgressHandlerPage.ashx was not found or does not implement IController
- Internal Error. Unable to find the X resource in the Y
- A primary key field specified using the KeyFieldName property is not found
- The ‘Key expression is undefined’ error occurs when you use GridViewExtension.BindToLINQ / GridViewExtension.BindToEF methods
- ‘The X has no access to path Y’ or ‘Access to the path X is denied’ (Image and File Extensions)
- Why redirect to another page or View does not work on AJAX requests
- Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery, DbRawSqlQuery) is not supported
- An alert message with the HTML/JavaScript/CSS content appears when you use callback-aware extensions
- An extension with ‘X’ name is already rendered
- ‘System.Web.WebPages.Html.HtmlHelper’ does not contain a definition for ‘DevExpress’
- The call is ambiguous between the following methods or properties: ‘DevExpress.Web.Mvc.UI.HtmlHelperExtension.DevExpress<ModelType>’
- Cannot convert lambda expression to type X because it is not a delegate type
Installation and Update Issues
- Type ‘X’ exists in both assemblies / Type ‘X’ is ambiguous in namespace ‘Y’
- Could not load file or assembly ‘X’
- Cannot modify the Global Assembly Cache
- Could not load file or assembly System.Web.Mvc or one of its dependencies
- Inheritance security rules violated by type: ‘DevExpress.Web.Mvc.DevExpressEditorsBinder’. Derived types must either match the security accessibility of the base type or be less accessible.
- Why the ‘Insert DevExpress MVC Extension’ option can be missing in the DevExpress section of Visual Studio’s main menu and in the context menu in an MVC 5 project