Zecwallet fullnode opens with no data, and error about AddressBook.json

[AArnott]

Zecwallet Fullnode v1.8.1

ZecWallet opens with no data displayed. The debugging panel is open and shows an error about this file that does not exist: C:\Users\andarno\AppData\Roaming\Zcash\AddressBook.json

The error is right, in that the file really does not exist. How is this file normally expected to be created?

[AArnott]

When I create the missing file with the content {}, that error goes away but in its place I get:

index.tsx:153 Throttling navigation to prevent the browser from hanging. See https://crbug.com/1038223. Command line switch --disable-ipc-flooding-protection can be used to bypass the protection