Fail detailed here:
https://www.msofficeforums.com/word/...e-address.html
UNlike [ and } fails, the # case is seems not due to faulty address creation, but I wonder if there is a correct address encoding and hence a macro could provide it.
An oddity is hyperlink.Address seems to be fibbing:
This doesn't prevent VBA changing the value. But follow fasil on both the requested and reported .Address files regardless, so the cause seems downstream.