I don’t seem to be able to get the synchronisation between my Blackberry and Zoho Calendar to work.

I have looked at different posts that recommend different downloads/links as per below:

https://msync.zoho.com/bbsync

https://mobilesync.wiki.zoho.com/blackberry.html

http://zsync.zohosites.com/BlackBerry.html

Tried each link separately.  Installed the app – trailed it – didn’t work and uninstalled it and installed the next one etc.

Problem is that events in Zoho are not synced in to my Blackberry calendar and the events in my Blackberry are not synchronised with my Zoho calendar. 

Can someone please help me with this. Which link should I use or is there another one I have not found? Does Zoho sync work at all with Blackberry these days?