Get started for free
Developer Tools and Languages
Visual Studio 2012
Visual Basic and Visual C#
Visual Basic
Visual Basic Reference
Visual Basic Language Reference
Error Messages
'#ElseIf' must be preceded by a matching '#If' or '#ElseIf'
'#Region' and '#End Region' statements are not valid within method bodies/multiline lambdas
'<attribute>' cannot be applied because the format of the GUID '<number>' is not correct
'<classname>' is not CLS-compliant because the interface '<interfacename>' it implements is not CLS-compliant
'<elementname>' is obsolete (Visual Basic Warning)
'<eventname>' is an event, and cannot be called directly
'<expression>' cannot be used as a type constraint
'<functionname>' is not declared (Smart Device/Visual Basic Compiler Error)
'<interfacename>.<membername>' is already implemented by the base class '<baseclassname>'. Re-implementation of <type> assumed
'<keyword>' is valid only within an instance method
'<membername>' cannot expose type '<typename>' outside the project through <containertype> '<containertypename>'
'<membername>' is ambiguous across the inherited interfaces '<interfacename1>' and '<interfacename2>'
<message> This error could also be due to mixing a file reference with a project reference to assembly '<assemblyname>'
'<methodname>' has multiple definitions with identical signatures
'<name>' is ambiguous in the namespace '<namespacename>'
'<name1>' is ambiguous, imported from the namespaces or types '<name2>'
<proceduresignature1> is not CLS-compliant because it overloads <proceduresignature2> which differs from it only by array of array parameter types or by the rank of the array parameter types
<type1>'<typename>' must implement '<membername>' for interface '<interfacename>'
<type1>'<typename>' must implement '<methodname>' for interface '<interfacename>'
'<typename>' cannot inherit from <type> '<basetypename>' because it expands the access of the base <type> outside the assembly
'<typename>' is a delegate type
'<typename>' is a type and cannot be used as an expression
A double quote is not a valid comment token for delimited fields where EscapeQuote is set to True
A property or method call cannot include a reference to a private object, either as an argument or as a return value
A reference was created to embedded interop assembly '<assembly1>' because of an indirect reference to that assembly from assembly '<assembly2>'
A startup form has not been specified
Access of shared member through an instance; qualifying expression will not be evaluated
'AddressOf' operand must be the name of a method (without parentheses)
An unexpected error has occurred because an operating system resource required for single instance startup cannot be acquired
Anonymous type member name can be inferred only from a simple or qualified name with no arguments
Argument not optional (Visual Basic)
Array bounds cannot appear in type specifiers
Array declared as for loop control variable cannot be declared with an initial size
Array subscript expression missing
Arrays declared as structure members cannot be declared with an initial size
'As Any' is not supported in 'Declare' statements
Attribute '<attributename>' cannot be applied multiple times
Automation error
Bad checksum value, non hex digits or odd number of hex digits
Bad DLL calling convention
Bad file mode
Bad file name or number
Bad record length
Because this call is not awaited, the current method continues to run before the call is completed
Cannot convert anonymous type to expression tree because it contains a field that is used in the initialization of another field
Cannot create ActiveX Component
Cannot refer to '<name>' because it is a member of the value-typed field '<name>' of class '<classname>' which has 'System.MarshalByRefObject' as a base class
Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class
Can't create necessary temporary file
Can't open '<filename>' for writing
Class '<classname>' cannot be found
Class does not support Automation or does not support expected interface
'Class' statement must end with a matching 'End Class'
Clipboard format is not valid
Constant expression not representable in type '<typename>'
Constants must be of an intrinsic or enumerated type, not a class, structure, type parameter, or array type
Constructor '<name>' cannot call itself
Copying the value of 'ByRef' parameter '<parametername>' back to the matching argument narrows from type '<typename1>' to type '<typename2>'
'Custom' modifier is not valid on events declared without explicit delegate types
Data type(s) of the type parameter(s) cannot be inferred from these arguments
Declaration expected
Default property '<propertyname1>' conflicts with default property '<propertyname2>' in '<classname>' and so should be declared 'Shadows'
Default property access is ambiguous between the inherited interface members '<defaultpropertyname>' of interface '<interfacename1>' and '<defaultpropertyname>' of interface '<interfacename2>'
Delegate class '<classname>' has no Invoke method, so an expression of this type cannot be the target of a method call
Derived classes cannot raise base class events
Device I/O error
'Dir' function must first be called with a 'PathName' argument
End of statement expected
Error creating assembly manifest: <error message>
Error creating Win32 resources: <error message>
Error in loading DLL (Visual Basic)
Error saving temporary Win32 resource file '<filename>': <error message>
Errors occurred while compiling the XML schemas in the project
Evaluation of expression or statement timed out
Event '<eventname1>' cannot implement event '<eventname2>' on interface '<interface>' because their delegate types '<delegate1>' and '<delegate2>' do not match
Events cannot be declared with a delegate type that has a return type
Events of shared WithEvents variables cannot be handled by non-shared methods
Expression does not produce a value
Expression has the type '<typename>' which is a restricted type and cannot be used to access members inherited from 'Object' or 'ValueType'
Expression is a value and therefore cannot be the target of an assignment
Expression of type <type> is not queryable
Expression recursively calls the containing property '<propertyname>'
Expression too complex
'Extension' attribute can be applied only to 'Module', 'Sub', or 'Function' declarations
File already open
File is too large to read into a byte array
File name or class name not found during Automation operation (Visual Basic)
File not found (Visual Basic Run-Time Error)
First operand in a binary 'If' expression must be nullable or a reference type
First statement of this 'Sub New' must be a call to 'MyBase.New' or 'MyClass.New' (No Accessible Constructor Without Parameters)
First statement of this 'Sub New' must be an explicit call to 'MyBase.New' or 'MyClass.New' because the '<constructorname>' in the base class '<baseclassname>' of '<derivedclassname>' is marked obsolete: '<errormessage>'
'For Each' on type '<typename>' is ambiguous because the type implements multiple instantiations of 'System.Collections.Generic.IEnumerable(Of T)'
Friend assembly reference <reference> is invalid
Function '<procedurename>' doesn't return a value on all code paths
Function evaluation is disabled because a previous function evaluation timed out
Generic parameters used as optional parameter types must be class constrained
'Get' accessor of property '<propertyname>' is not accessible
Handles clause requires a WithEvents variable defined in the containing type or one of its base types
Identifier expected
Identifier is too long
Initializer expected
Input past end of file
Internal error happened at <location>
Implicit conversion from '<typename1>' to '<typename2>' in copying the value of 'ByRef' parameter '<parametername>' back to the matching argument.
'Is' requires operands that have reference types, but this operand has the value type '<typename>'
'IsNot' operand of type 'typename' can only be compared to 'Nothing', because 'typename' is a nullable type
Labels that are numbers must be followed by colons
Lambda expression will not be removed from this event handler
Lambda expressions are not valid in the first expression of a 'Select Case' statement
Late bound resolution; runtime errors could occur
Latebound overload resolution cannot be applied to '<procedurename>' because the accessing instance is an interface type
Leading '.' or '!' can only appear inside a 'With' statement
Line is too long
'Line' statements are no longer supported (Visual Basic Compiler Error)
Method does not have a signature compatible with the delegate
Methods of 'System.Nullable(Of T)' cannot be used as operands of the 'AddressOf' operator
'Module' statements can occur only at file or namespace level
Name <membername> is not CLS-compliant
Name '<name>' is not declared
Name <namespacename> in the root namespace <fullnamespacename> is not CLS-compliant
Namespace or type specified in the Imports '<qualifiedelementname>' doesn't contain any public member or cannot be found
Namespace or type specified in the project-level Imports '<qualifiedelementname>' doesn't contain any public member or cannot be found
Need property array index
Nested function does not have a signature that is compatible with delegate '<delegatename>'
No accessible 'Main' method with an appropriate signature was found in '<name>'
Non-CLS-compliant <membername> is not allowed in a CLS-compliant interface
Nullable type inference is not supported in this context
Number of indices exceeds the number of dimensions of the indexed array
Object or class does not support the set of events
Object required
Object variable or With block variable not set
Operator declaration must be one of: +,-,*,\,/,^, &, Like, Mod, And, Or, Xor, Not, <<, >>, =, <>, <, <=, >, >=, CType, IsTrue, IsFalse
'Optional' expected
Optional parameters must specify a default value
Ordinal is not valid
Out of memory (Visual Basic Compiler Error)
Out of stack space (Visual Basic)
Out of string space (Visual Basic)
Overflow (Visual Basic Error)
Overflow (Visual Basic Run-Time Error)
Path not found
Path/File access error
Permission denied (Visual Basic)
Procedure call or argument is not valid (Visual Basic)
Property '<propertyname>' doesn't return a value on all code paths
Property array index is not valid
Property let procedure not defined and property get procedure did not return an object
Property not found
Property or method not found
Range variable <variable> hides a variable in an enclosing block, a previously defined range variable, or an implicitly declared variable in a query expression
Range variable name can be inferred only from a simple or qualified name with no arguments
Reference required to assembly '<assemblyidentity>' containing type '<typename>', but a suitable reference could not be found due to ambiguity between projects '<projectname1>' and '<projectname2>'
Reference required to assembly '<assemblyname>' containing the base class '<classname>'
Resume without error
Return type of function '<procedurename>' is not CLS-compliant
'Set' accessor of property '<propertyname>' is not accessible
Some subkeys cannot be deleted
Statement cannot end a block outside of a line 'If' statement
Statement is not valid in a namespace
Statement is not valid inside a method/multiline lambda
String constants must end with a double quote
Structure '<structurename>' must contain at least one instance member variable or at least one instance event declaration not marked 'Custom'
'Sub Main' was not found in '<name>'
Sub or Function not defined (Visual Basic)
Subscript out of range (Visual Basic)
TextFieldParser is unable to complete the read operation because maximum buffer size has been exceeded
The type for variable '<variablename>' will not be inferred because it is bound to a field in an enclosing scope
This array is fixed or temporarily locked (Visual Basic)
This key is already associated with an element of this collection
Too many files
Type '<typename>' has no constructors
Type <typename> is not CLS-compliant
Type '<typename>' is not defined
Type arguments could not be inferred from the delegate
Type mismatch (Visual Basic)
Type of '<variablename>' cannot be inferred because the loop bounds and the step variable do not widen to the same type
Type of member '<membername>' is not CLS-compliant
Type of optional value for optional parameter <parametername> is not CLS-compliant
Type of parameter '<parametername>' is not CLS-compliant
Type parameters cannot be used as qualifiers
Unable to create strong-named assembly from key file '<filename>': <error>
Unable to embed resource file '<filename>': <error message>
Unable to emit assembly: <error message>
Unable to find required file '<filename>'
Unable to get serial port names because of an internal system error
Unable to link to resource file '<filename>': <error message>
Unable to load information for class '<classname>'
Unable to write output to memory
Unable to write temporary file because temporary path is not available
Unable to write to output file '<filename>': <error>
Underlying type <typename> of Enum is not CLS-compliant
Using the iteration variable in a lambda expression may have unexpected results
Value of type '<typename1>' cannot be converted to '<typename2>'
Value of type '<typename1>' cannot be converted to '<typename2>' (Multiple file references)
Value of type 'type1' cannot be converted to 'type2'
Variable '<variablename>' hides a variable in an enclosing block
Variable '<variablename>' is used before it has been assigned a value
Variable uses an Automation type not supported in Visual Basic
XML axis properties do not support late binding
XML comment exception must have a 'cref' attribute
XML entity references are not supported
XML literals and XML properties are not supported in embedded code within ASP.NET
XML namespace URI 'http://www.w3.org/XML/1998/namespace' can be bound only to 'xmlns'
Expand Minimize
This topic has not yet been rated - Rate this topic

Optional parameters must specify a default value

Visual Studio 2012

Optional parameters must provide default values that can be used if no parameter is supplied by a calling procedure.

Error ID: BC30812

To correct this error

  • Specify default values for optional parameters; for example:

    Copy 
    Sub Proc1(ByVal X As Integer, 
      Optional ByVal Y As String = "Default Value")
   MsgBox("Default argument is: " & Y)
End Sub
Did you find this helpful?
(1500 characters remaining)
© 2013 Microsoft. All rights reserved.