Not able to import custom less file in theme.less in magento 2.1.1

[MukeshIndurkar]

I have updated to Magento 2.1.1 

I have crated a new theme and added _theme.less. Changes in _theme.less are reflecting but when i am trying to import custom less file in _theme.less, grunt is not compiling it.

Any idea how to resolve it.

[Cosnett]

What is version of Magento before you upgrade to magento 2.1.1? Maybe there are some conflicts on theme after you upgrade