Windows Forms Designer Error Messages

The following is a list of the errors messages you may encounter when using the Windows Forms Designer in Visual Studio.

In This Section

Topic	Location
'<identifier name>' is not a valid identifier	Windows Forms Programming
'<name>' already exists in '<project name>'	Windows Forms Programming
'<Toolbox tab name>' is not a toolbox category	Windows Forms Programming
A requested language parser is not installed	Windows Forms Programming
A service required for generating and parsing source code is missing	Windows Forms Programming
An exception occurred while trying to create an instance of '<object name>'	Windows Forms Programming
Another editor has '<document name>' open in an incompatible mode	Windows Forms Programming
Another editor has made changes to '<document name>'	Windows Forms Programming
Another editor has the file open in an incompatible mode	Windows Forms Programming
Array rank '<rank in array>' is too high	Windows Forms Programming
Assembly '<assembly name>' could not be opened	Windows Forms Programming
Bad element type. This serializer expects an element of type '<type name>'.	Windows Forms Programming
Cannot access the Visual Studio Toolbox at this time	Windows Forms Programming
Cannot bind an event handler to the '<event name>' event because it is read-only	Windows Forms Programming
Cannot create a method name for the requested component because it is not a member of the design container	Windows Forms Programming
Cannot name the object '<name>' because it is already named '<name>'	Windows Forms Programming
Cannot remove or destroy inherited component '<component name>'	Windows Forms Programming
Category '<Toolbox tab name>' does not have a tool for class '<class name>'	Windows Forms Programming
Class '<class name>' has no matching constructor	Windows Forms Programming
Code generation for property '<property name>' failed	Windows Forms Programming
Component '<component name>' did not call Container.Add() in its constructor	Windows Forms Programming
Component name cannot be empty	Windows Forms Programming
Could not access the variable '<variable name>' because it has not been initialized yet	Windows Forms Programming
Could not find type '<type name>'	Windows Forms Programming
Could not load type '<type name>'	Windows Forms Programming
Could not locate the project item templates for inherited components	Windows Forms Programming
Delegate class '<class name>' has no invoke method. Is this class a delegate?	Windows Forms Programming
Duplicate declaration of member '<member name>'	Windows Forms Programming
Error reading resources from the resource file for the culture '<culture name>'	Windows Forms Programming
Error reading resources from the resource file for the default culture '<culture name>'	Windows Forms Programming
Failed to parse method '<method name>'	Windows Forms Programming
Invalid component name: '<component name>'	Windows Forms Programming
The assembly '<assembly name>' could not be found	Windows Forms Programming
The assembly name '<assembly name>' is invalid	Windows Forms Programming
The base class '<class name>' cannot be designed	Windows Forms Programming
The base class '<class name>' could not be loaded	Windows Forms Programming
The class '<class name>' cannot be designed in this version of Visual Studio	Windows Forms Programming
The class name is not a valid identifier for this language	Windows Forms Programming
The component cannot be added because it contains a circular reference to '<reference name>'	Windows Forms Programming
The designer cannot be modified at this time	Windows Forms Programming
The designer could not be shown for this file because none of the classes within it can be designed	Windows Forms Programming
The designer for base class '<class name>' is not installed	Windows Forms Programming
The designer inspected the following classes in the file:	Windows Forms Programming
The designer must create an instance of type '<type name>', but it can't because the type is declared as abstract	Windows Forms Programming
The file could not be loaded in the designer	Windows Forms Programming
The following exception has occurred:	Windows Forms Programming
The language for this file does not support the necessary code parsing and generation services	Windows Forms Programming
The language parser class '<class name>' is not implemented properly	Windows Forms Programming
The name '<name>' is already used by another object	Windows Forms Programming
The object '<object name>' does not implement the IComponent interface	Windows Forms Programming
The object '<object name>' returned null for the property '<property name>' but this is not allowed	Windows Forms Programming
The serialization data object is not of the proper type	Windows Forms Programming
The service '<service name>' is required, but could not be located	Windows Forms Programming
The service instance must derive from or implement '<interface name>'	Windows Forms Programming
The text in the code window could not be modified	Windows Forms Programming
The Toolbox enumerator object only supports retrieving one item at a time	Windows Forms Programming
The Toolbox item for '<component name>' could not be retrieved from the Toolbox	Windows Forms Programming
The Toolbox item for '<Toolbox item name>' could not be retrieved from the Toolbox	Windows Forms Programming
The type '<type name>' could not be found	Windows Forms Programming
The type '<type name>' has no event named '<event name>'	Windows Forms Programming
The type '<type name>' has no field named '<field name>'	Windows Forms Programming
The type '<type name>' has no property named '<property name>'	Windows Forms Programming
The type resolution service may only be called from the main application thread	Windows Forms Programming
The variable '<variable name>' is either undeclared or was never assigned	Windows Forms Programming
There is already a command handler for the menu command '<menu command name>'	Windows Forms Programming
There is already a component named '<component name>'	Windows Forms Programming
There is already a Toolbox item creator registered for the format '<format name>'	Windows Forms Programming
This language engine does not support a CodeModel with which to load a designer	Windows Forms Programming
Type '<type name>' does not have a constructor with parameters of types '<parameter type names>'	Windows Forms Programming
Unable to add reference '<reference name>' to the current application	Windows Forms Programming
Unable to check out the current file	Windows Forms Programming
Unable to find page named '<Options dialog box tab name>'	Windows Forms Programming
Unable to find property '<property name>' on page '<Options dialog box tab name>'	Windows Forms Programming
Unable to load assembly '<assembly name>'	Windows Forms Programming
Visual Studio cannot open a designer for the file because the class within it does not inherit from a class that can be visually designed	Windows Forms Programming
Visual Studio cannot save or load instances of the type '<type name>'	Windows Forms Programming
Visual Studio is unable to open '<document name>' in Design view	Windows Forms Programming
Visual Studio was unable to find a designer for classes of type '<type name>'	Windows Forms Programming