Duplicate add-on ID found (Replacing outdated spellchecker)

I have created a Māori spell check dictionary to replace https://addons.mozilla.org/en-US/firefox/addon/te-papakupu-māori/
Repeated attempts to contact the original author have failed.

When uploading the .xpi file everything checks out fine apart from this error message
’Duplicate add-on ID found’

I am assuming that this is because I am using mi-NZ@dictionaries.addons.mozilla.org as the id.

Please indicate how I should proceed. TIA Graham

Hello,

you need to change the ID in your install manifest to something else.