Out of range in Word

There could be many reasons such as:
- there is no active document or it has changed at the moment the code is executed
- the document has multiple sections etc.

However in order to solve the problem more information would be needed. So in my opinion you should wrap the operations inside a try...catch block and in case of an error gather all the information possible about the situation.

Another thing that could make the code more robust is that you would store the references inside a variable instead of referencing Active... For example in the beginning of the code set the ActiveDocument value in a Word.Document type of variable and use that variable to make modifications to the document. This often eliminates problems that occur when the active document changes.