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 detailed information about an issue, see the instructions listed in the following topic:
- 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
#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
- The 'Microsoft JScript runtime error: 'X' is undefined' error message appears when the Control.Visible 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
- Cannot unregister UpdatePanel with ID since it was not registered with the ScriptManager
#Installation and Update Issues
- Cannot modify the Global Assembly Cache
- Type 'X' exists in both assemblies / Type 'X' is ambiguous in namespace 'Y'
- Could not load file or assembly 'Microsoft.Windows.Design.Extensibility ...'
- Could not load file or assembly 'X'
#Performance Issues
#Grid-Related Issues
- How to: Improve Grid Performance
- The 'Specified method is not supported' and 'Updating is not supported by data source 'X' unless UpdateCommand is specified' errors occur
- Grid displays empty rows in database server mode
- The Click event of asp:ImageButton is not raised when the component is located inside a template
- The 'Row not found or changed' error occurs
- This action has been disabled for security reasons. The control cannot serialize complex primary key field values
- Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed