LIGHTNING Calendar stopped synchronising. Getting faillure message
Since this morning synchronising of my Lightning calendar with one of my google calendars has become problematic. That is, when entering a new event into Lightning it will not sync with the google calendar, or very slowly, and/or partially. It will for instance sync with my android calendar, after some waiting, but not with the google calendar from the same account on the web. Moreover I keep getting messages from Thunderbird/Lightning (?) that "...a failure has occurred whilst writing to the calendar Rondte" (the latter is my account name). When hitting the 'detials' button on that failure message a new message appears saying that the 'failure code' (I am translating from the Dutch) is 'MODIFICATION_FAILED' .. .
This is all I can find.
The google account itself seems to be o.k. Gmail is working and other Google Services too.