Notes....

I'm just shooting from the hip here.

If it were me based on your comments above:
1) make sure Sync Toy is Uninstalled completely....reboot.
2) After reboot...click on Windows Update and let it do it's thing to make sure you're current with Windows Updates...reboot it necessary.
3) After reboot....disable any anti-virus programs running in the background.
4) Now try to install your new app.
5) If it goes well, reboot to be sure it installed properly and to re-engage your anti virus programs and start afresh.

Again...just a protocol I've come to adhere to by default when it comes to installing new apps....some can be quite finicky as we all know.
Hopefully others will have some ideas too.

Carry on....I need more coffee.

No guarantee I'm correct but it's still a good starting point.
Hope all goes well....