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

See Also

Concepts

Design-Time Errors in the Windows Forms Designer