K2 is not installed or any K2 categories are available

I changed the The News Show Pro Tumbnails cache time from 30m to 3m..Since then l am getting this error at k2 categories from news show datasource settings:

"K2 is not installed or any K2 categories are available"

But l have checked k2 items and they are all there . Can someone help me please

What happens when you change cache time back to 30m?