The last version of Qt that had QWebView was 5.5. This app won't build in any version newer than that. Qt Creator 3.5.1 goes with that.
Windows: https://download.qt.io/new_archive/qt/5.5/5.5.1/qt-opensource-windows-x86-mingw492-5.5.1.exe Be sure to install MinGW as part of the installer process.
Linux - can't be installed because of OpenSSH incompatibility: https://download.qt.io/new_archive/qt/5.5/5.5.1/qt-opensource-linux-x64-5.5.1.run