Isaac and I have attempted upgrade from v7.6.0 to v188.8.131.52 via the upgrade utility on the stock (US) English language files with no issues; you should patch any non US English language files outside of the upgrade utility.
It is important to note that you cannot copy paste from the installer page as it processes the HTML from the language files in the warning messages area; you'll need to grab any language strings directly from the language files.
We tested with
"Languages - Let the upgrader upgrade these for you"
"Update My Language Files"
"I Have Updated My Language Files By Hand "
The official upgrade documentation (with screenshots) is available at https://www.ubbcentral.com/doc_upgrade7.php