ical errors interfacing with Yahoo! and gmail calendars

I am getting various errors interfacing between ical on my mac mini and gmail and Yahoo.

The image above is an example of the kind of error message I get.

Also, tho, notifications do not transfer properly between my Android phone and ical.  The appointments transfer, but the notifications do not.  This makes the calendar substantially less useful, even dysfunctional.

I am very dissatisfied here. I thought Apple was a good company with long lasting products.

Now I'm finding the compatibility issues unmanageable.

Also I feel that google does not do enough to ensure compatibility with different platforms. I am also finding problems interfacing with Yahoo! mail using the chrome browser and the Yahoo! app for Android.  I suspect that this is partly due to google not working hard enough to be compatible.