Customer Installed Build 237 on one server, and as an admin could can get the screen indicating it is Build 237 by clicking the "About" link, but as an standard, secured user, it returned nothing. Later they found users cannot search for page, cannot find text in a report, cannot save as PDF. CommonTools.js was missing.
Web Viewer 12.1 Build 237 in Windows 2016 Server
Product updates must NOT be executed from within the application home directory. Executing the same update from outside of the application Home directory resolved the problems.