Grunt karma gets an error .... Loading tasks "grunt-karma.js" ... ERROR

Question

Loading tasks "grunt-karma.js" ... ERROR

TypeError: Unable to read the 'prototype' property from undefined Warning: Karma task not found. Use -force to continue.

Interrupted due to warnings.

I also have this problem. I am using node 7.5.0 and npm 4.1.2.

Answer 1

I had a similar problem. The following correction helped me

"grunt-karma": "^0.12.2",
"karma": "^1.6.0",

More here

Answer 2

Performing npm installation in karma helped me fix this problem.