Hello,
I have the pro licence and got my Caldav calendar to work on my main computer, but after many attempts it’s impossible to get it to work on my laptop.
I have the same version on both computers (10.4.5326 (97a2e75)) and enter the same info and parameters (CALDAV URL, password, etc). I tried creating a new account couple of times but I can’t get the laptop to sync.
Your help would be greatly appreciated.
Thank you in advance.
Suggest then if you want the same CalDAV calendar & same mail accounts etc as on your main computer, then make a backup via “Menu / Backup” which by default saves a dated backup zip file in your “Documents / eM Client” folder. You can see when the backup is completed in Show Operations via the dropdown on the right of Refresh.
Then copy that dated backup file to your laptop same folder and restore the backup via “Menu / File / Restore”. It will then be exactly the same.
If you have a difference license on your second computer then after restoring, go to “Menu / Help “License” and deactivate and then reactivate with the license key for the laptop if it’s different.
Oh! That’s a great idea. I’m going to try this option asap.
Thanks a lot ! 
Well, @cyberzork, you made my day!
I now have my CalDav calendar on both computers! You rock!
Thank you a million times