Troubleshooting
- 2 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 topic:
Common Issues
Client-Side Issues
- The 'X is undefined' error occurs or controls are rendered with incorrect styles
- Cannot access DevExpress ASP.NET controls on the client
- The 'ReferenceError: 'X' is not defined' error message appears when the Control.Enabled property is set to false
Server-Side Issues
- Cannot add duplicate collection entry of type 'add' with unique key attribute 'name' set to 'ASPxHttpHandlerModule'
- Icons, images, and scripts are missing
- The target 'X' for the callback could not be found or did not implement ICallbackEventHandler
- The controller for ASPxUploadProgressHandlerPage.ashx was not found or does not implement IController
- Internal Error. Unable to find the X resource in the Y
- Response.Redirect cannot be called in a Page callback
- Why it is impossible to download files on callbacks
- A primary key field specified using the KeyFieldName property is not found
- The 'Key expression is undefined' error occurs when you use LinqServerModeDataSource / EntityServerModeDataSource
- Data binding methods such as Eval(), XPath(), and Bind() can only be used for a databound control
- Could not find control 'X' in ControlParameter 'Y'
- 'The X has no access to path Y' or 'Access to the path X is denied' for File and Image Controls
- The 500.19 error - The requested page cannot be accessed because the related configuration data for the page is invalid
Installation and Update Issues
- Cannot modify the Global Assembly Cache
- Type 'X' exists in both assemblies / Type 'X' is ambiguous in namespace 'Y'