You are downloading the Upgrade Advisor AppX file v188.8.131.52 for Windows Phone. Upgrade Advisor is a free and useful Productivity app: The Windows 10 Mobile Upgrade Advisor app helps you find out if your Windows Phone 8.1 phone is eligible to install the upgrade to Windows 10 Mobile. ... You can now download the offline AppX file to install & try it.
Download Locations for Upgrade Advisor 184.108.40.206 AppX file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline AppX File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Upgrade Advisor AppX file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.