This may be old, but still quite valid. In my case I hadn't used my Win10 tablet for a number of months, prompting windows updates and for space reasons an automated cleanup of the temp dir, which deleted the previous evernote.msi file. Upgrading wouldn't work, uninstalling wouldn't either.
For this situation I've found another workaround: find the installer for the exact version you have (help -> about) here on the forums (fortunately they're still downloadable, google gives better results, using a query like site:discussion.evernote.com 6.11.2 download), and run that installer again. The correct msi should now be present, after which you can uninstall it, and then install the latest version. I haven't tried immediately upgrading, but I assume that will work too now.
Note to the Evernote team: Win10 has a 'device performance & health' feature that by default is set to clean out the temp dir whenever windows requires it (more often if the user specifies so, for example weekly or monthly).
It would be helpful if the installer detects which previous version of evernote is present (which may be older than the second to last release), then downloads that specific msi to the temp dir. After that, both repairs, uninstalls and upgrades should work as intended again.