为什么我会收到“运行时错误 '13'：类型不匹配”错误消息？

Question

I am very new to VBA and still learning programming languages and coding. I came up with the following code for my project after reffering several online tutorials and threads. When I run the code I get an error message saying,Run-time Error: Type mismatch.If anyone of you experts could help me to find the error, it would be highly appreciated.

Thanks a lot in advance

Dim wsServiceRegistry As Worksheet, wsInhouseMaterialInventory As Worksheet
Dim updateCell As Range
Dim emptyRow As Long

With ThisWorkbook
    Set wsServiceRegistry = .Worksheets("Service Registry")
    Set wsInhouseMaterialInventory = .Worksheets("Inhouse Material Inventory")
End With

Set updateCell = wsInhouseMaterialInventory.Cells(Me.InhouseMaterialComboBox.ListIndex + 2, 4)
updateCell.Value = updateCell.Value - Val(Me.MaterialQuantityTextBox.Value)


If updateCell.Value < 1 Then updateCell.EntireRow.Delete: Exit Sub

Answer 1

The only line that can cause a type mismatch here is
updateCell.Value = updateCell.Value - Val(Me.MaterialQuantityTextBox.Value) , depending on what the cell contains.

The first thing to find out, is if it is the cell you actually want and if it contains what you expect. Add these lines just above the line in question:

Debug.Print updateCell.Address
Debug.Print updateCell.Value

Press Ctrl + G to show the debug output and run it. If the output matches your expectation, then you'll have to use the Val function again, like this:

updateCell.Value = Val(updateCell.Value) - Val(Me.MaterialQuantityTextBox.Value)

forcing the updateCell to become something you can subtract from.