What does the ESLint error "Definition for rule 'padding-line-between-statements' was not found" mean?

Pretty much what the title says. I have the following rule in my .eslintrc.js file (among others)

 "padding-line-between-statements": [
  "error",
  {
    "blankLine": "always",
    "prev": "*",
    "next": "if"
  },
],

and on running a test suite (not written by me) I get 99 (!) errors, all the same, for 99 different files:

  6:1  error  Definition for rule 'padding-line-between-statements' was not found  padding-line-between-statements

I am new to using ESlint, and I am a bit lost. This all worked fine before -- meaning, the test suite, the last time I ran it, gave other errors, but not this string of "definition not found" errors. What is it that it indicates, and how might I fix it? I was running ESlint version 4.5.0 and thought perhaps I needed to update it when I first got the errors -- it's now version 4.7.0, but no change. FWIW I'm running node 6.3.1 and npm 3.10.3 -- thanks for any insight!