FWIW, I get the same error message but opt for the Cancel button and hope for the best. Everything works on the desktop version of the google calendar in the stock browser and in Dolphin. The only noticeable difference is in portrait mode, the right side of the calendar which would have a scroll bar on a PC is just truncated and left open. It runs smooth and fast, allows viewing of all my different events on eight different color coded calendars, every calendar view works (i.e.: day, week, month, etc..), and allows creating events.

I was hung up on that error message for a while and kept clicking OK without reading it fully. The first time I clicked cancel, it made me wonder why it's even there. Hope this helps!