Endnote X7 reinstallation - product key not working

hi everyone,
sorry in case this subject had already been discussed and thank you for pointing me to the proper place.

i had an installation of EN v.7 on a Mac with Sierra and Word v. 15.23.

i changed the mac, and it has Mojave. i backed up all the applications (including Office and EndNote). 
i had to reinstall the whole Office, and downgraded Word from v. 16.xx to v. 15.83 which is the highest working version with EN v.7. but the installed version of Endnote restored from backup didn’t work - some buttons remained inactive.

s,o very confident as i had my product key registered, i started the reinstallation of Endnote v.7 but at the moment of starting the installation my product key was refused as “not working”.

does anyone can help me? for example checking to which version of EN my product key is attached (i am pretty sure that it is v. 7.8 as this one was installed on my previous mac), or to understand why i cannot reinstall EN v.7 even if i have a legally purchades product key?

thank you so much for your help

best

maurizio

I would suggest you download and install from our website EndNote X7.

https://support.clarivate.com/Endnote/s/article/EndNote-Installer-download?language=en_US

If you still have trouble installing with this installer then please contact Technical Support directly.

1-800-336-4474 option 4 then 1

or

https://support.clarivate.com/Endnote/s/technicalsupport?language=en_US