Fix Runtime Error 91 In Vba: Object Not Set

Fixing Runtime Error 91 in VBA: Object Not Set

Runtime Error 91, also known as "Object Not Set," is a common error in Visual Basic for Applications (VBA) that occurs when a variable or object is not properly initialized or set before being used. In this article, we will discuss the causes of this error and provide step-by-step solutions to fix it.

What causes Runtime Error 91?

Runtime Error 91 can occur due to various reasons, including:

1. Uninitialized variables: When a variable is declared but not initialized, VBA throws a Runtime Error 91.
2. Incorrect object references: If an object reference is incorrect or not set, VBA will throw this error.
3. Early binding vs. late binding: If you are using late binding, you might encounter this error if the object is not created or set.
4. Worksheet or workbook issues: Problems with worksheets or workbooks, such as incorrect indexing or non-existent sheets, can also cause this error.

How to fix Runtime Error 91?

To fix Runtime Error 91, follow these steps:

1. Initialize Variables

Make sure to initialize variables before using them. Use the Set keyword to assign a value to an object variable.

Dim ws As Worksheet
Set ws = ThisWorkbook.Worksheets("Sheet1")

2. Verify Object References

Check that object references are correct and properly set. Ensure that the object exists and is accessible.

Dim rng As Range
Set rng = ws.Range("A1")

3. Use Early Binding

Consider using early binding instead of late binding to avoid errors. Early binding allows you to create objects at compile-time, which can help prevent errors.

Dim app As New Excel.Application

4. Check Worksheet and Workbook References

Verify that worksheet and workbook references are correct and exist. Use Worksheets or Workbook objects to access specific sheets or workbooks.

Dim wb As Workbook
Set wb = Workbooks.Open("C:\Example.xlsx")
Dim ws As Worksheet
Set ws = wb.Worksheets("Sheet1")

5. Debug Your Code

Use the VBA debugger to step through your code and identify the line that throws the error. This will help you pinpoint the cause of the error.

6. Use Error Handling

Implement error handling to catch and handle errors, such as On Error GoTo or Try...Catch blocks.

On Error GoTo ErrorHandler
    ' Code that might throw an error
Exit Sub
ErrorHandler:
    MsgBox "An error occurred: " & Err.Description

Example Code

Here's an example code that demonstrates how to fix Runtime Error 91:

Sub ExampleCode()
    Dim ws As Worksheet
    Set ws = ThisWorkbook.Worksheets("Sheet1") ' Initialize variable
    
    Dim rng As Range
    Set rng = ws.Range("A1") ' Verify object reference
    
    ' Use early binding
    Dim app As New Excel.Application
    
    ' Check worksheet and workbook references
    Dim wb As Workbook
    Set wb = Workbooks.Open("C:\Example.xlsx")
    Set ws = wb.Worksheets("Sheet1")
    
    ' Use error handling
    On Error GoTo ErrorHandler
    ' Code that might throw an error
    Exit Sub
ErrorHandler:
    MsgBox "An error occurred: " & Err.Description
End Sub

Conclusion

Runtime Error 91 can be frustrating, but by following these steps, you can identify and fix the issue. Remember to initialize variables, verify object references, use early binding, check worksheet and workbook references, debug your code, and implement error handling to prevent and handle errors.