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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:
- Get Started (How to collect detailed information about the issue)
- KB Article: How to enable script debugging
- How to inspect CSS rules
- 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
- 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'
- Could not load file or assembly 'Microsoft.Windows.Design.Extensibility ...'
- Could not load file or assembly 'X'
- 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