Ensure the file isn't actually named prod.keys.txt due to hidden file extensions in Windows.
The error means . You must dump prod.keys from your own Switch and place it in the working directory, ~/.switch/ , or specify its path with --keyset . Never download keys from untrusted sources. hactool prodkeys does not exist link
Older versions of hactool (pre-2018) used a different key format or filename. If you are using a very old build, it might be looking for keys.txt instead of prod.keys . Ensure the file isn't actually named prod
chmod 644 prod.keys
I can provide the exact command syntax for your task if you'd like. hactool prodkeys does not exist link