There is only one file type that uses the .UHTML extension:
UC Browser Saved Webpage
A UHTML file is a waved webpage created by UCWeb UC Browser, a web browser for mobile platforms, such as Android, iOS, and Chrome OS. It includes the webpage's HTML source code and images. UHTML files are used for saving webpage snapshots and can be viewed in UC Browser while offline.
Updated: September 19, 2020