> don't know which version

apparently, they forked from Qt 4.8 and QML is disabled in Copperspice. Ref:

https://www.copperspice.com/docs/cs_overview/timeline.html#t...

https://news.ycombinator.com/item?id=9685022

https://forum.copperspice.com/viewtopic.php?f=11&t=1152