The user has chosen to cancel because the system does not pass the compatibility scan to install the update. Setup.exe will report this error when it can upgrade the machine with user data but cannot migrate installed applications.
To identify the incompatible app, grab a Windows 10 install image (use Windows Media Creation Tool to download the appropriate Win 10 version) und mount it. Then execute the file setup.exe located in the root folder of the Win 10 install image. The upgrade
wizzard shall list incompatible apps.
In case, an unknown app is enlisted from upgrade troubleshooter, it's possible to analyze the xml files to find out more details. The steps are discussed within my blog posts.