I am currently running the free version 7.2.36908 for personal use (the newest version available) and I am unable to configure and use Google Calendar. 
I tried when I first installed eM Client and was not able to link to the calendar. I continually receive the above errors while using the client. Is it possible to link to the calendar, or if not, stop the errors from appearing?
Did you setup your calendar using Menu > Tools > Subscribe to Internet Calendar?
If the calendar is yours, why not add it as an account. Go to Menu > Tools > Accounts and add it like that.
Gary,
My account setup looks nothing like what you show. Here is the account setup from my version:
Click on the + icon in the bottom left of that window to add a new account. Then click on Calendar > Google Calendar.
That did it the calendar works, thanks Gary. However I am still getting the error window I included whenever I start the client and periodically while using the client.
I guess that means that one of the items in the calendar is in an invalid format. In the same pop-up with the error, if you click on the Log tab, you may find more information about what that item is.
I can’t see anything other than the actual error message in the log. I’ll see if it clears up. I’ll also look at the calendar in more detail to see if I can find anything. Thanks again.