Troubleshooting
- 3 minutes to read
In This Article
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