after syinc ,my calender opens for 5 seconds then closes

my calaender had not sync with icloud desite alway being turned on

Tried to sync with computer, this did'nt work

While IPad connected I tried to adjust settings on IPad

Switched off cloud, data from calender appeared on IPad calender then disappeared, I then adjusted settings again Ipad ( I think by this time gettig a bit upset)

discontected IPad , tried to open calender on Ipad and it just opens for a 5 secs or less, does not stay open