Selected Answer
"Permission denied" isn't an Excel problem. It refers to the permission you need to access files on your computer. Such permissions are controlled by Windows and set in Windows Explorer.
Take a look at this link to learn more.
Edit Jul 11 2020 ============================
The line of code that throws the error, .Column = sRng.Value, attempts to read from a worksheet and the permission is denied. That matches my suspiction exactly. However, it's true that VBA will sometimes not give the correct reason for an error. So, what to do if the error is caused by the code?
In fact, there is plenty of reason to suspect this to be the case. The column to which you wish to write isn't specified, and if it were, and presuming that it exists, you can't assign a worksheet column to a combobox column. You might try
ComboBox1.List = sRng.Value
.
However, while it's lovely to behold when it works, assigning an array to a ComboBox's List property doesn't always work Miscrosoft recommends to use the Add method and build the List item by item. Reading from an array you can do this in a loop, and it's very fast. But if you want to continue trying to assign the array directly, note that sRng.Value is a 2D array even if the range comprises of only a single row or column. You can quickly convert such an array to a 1D array using Excel's Transpose function.
Dim MyArray As Variant
MyArray = Application.Transpose(sRng.Value)
ComboBox1.List = Application.Transpose(MyArray)
You may need to transpose only once, depending upon whether your range is a row or a column. Try it out. While this method may not solve your problem but it will definitely clarify the issue. If your code is lacking a permission to read from the worksheet the same error will now occur on this line: MyArray = Application.Transpose(sRng.Value). On the other hand, if the lacking permission refers to writing to the ComboBox column you will now have a completely different kind of error which you can avoid by using the Add method.