Describe the problem. Be as specific as possible!:
When I go into my farm, only one of my 12 monsters is moving. The rest are stuck, doing their "standing" animation. When I go visit other people's farms, none of their monsters are moving.
It's not lag, because I can harvest my buildings and I can nurture or play with monsters normally - except they don't respond to (left) clicking.
When I visit my main farm from another account on another computer, all monsters behave normally.