The entities can be found in article https://www.ptc.com/en/support/article/CS299233 , there is a link under the last video.
Hi @AF_10333884 indeed it seems to be an issue with Chrome, it works ok for me in Firefox.
In Chrome, instead of clicking the link, right click on it and select Save As. Then change the extension of the file to twx instead of txt.
You should then be able to import this file in ThingWorx.