Failed to list Grunt tasks error in WebStorm

I am using JetBrains Webstorm 11.0.4 on Windows 7. I have a project with a Gruntfile.js file for which, when I attempt to have WebStorm "Reload Tasks", WebStorm fails with:

"! Failed to list tasks" in the Grunt pane.

The details of the error are:

Registering "C:\Program Files (x86)\JetBrains\WebStorm 11.0.4\plugins\JavaScriptLanguage\grunt_js\tasks" tasks.
Loading "grunt-tasks-fetcher.js" tasks...ERROR
>> Error: Couldn't find preset "es2015" relative to directory "C:\\Program Files (x86)\\JetBrains\\WebStorm 11.0.4\\plugins\\JavaScriptLanguage\\grunt_js\\tasks"
>>   at <my_project>\node_modules\babel-core\lib\transformation\file\options\option-manager.js:395:17
>>   at Array.map (native)
>>   at OptionManager.resolvePresets (<my_project>\node_modules\babel-core\lib\transformation\file\options\option-manager.js:387:20)
>>   at OptionManager.mergePresets (<my_project>\node_modules\babel-core\lib\transformation\file\options\option-manager.js:370:10)
>>   at OptionManager.mergeOptions (<my_project>\node_modules\babel-core\lib\transformation\file\options\option-manager.js:330:14)
>>   at OptionManager.init (<my_project>\node_modules\babel-core\lib\transformation\file\options\option-manager.js:488:10)
>>   at compile (<my_project>\node_modules\babel-register\lib\node.js:112:69)
>>   at loader (<my_project>\node_modules\babel-register\lib\node.js:158:14)
>>   at Object.require.extensions.(anonymous function) [as .js] (<my_project>\node_modules\babel-register\lib\node.js:168:7)
>>   at Module.load (<my_project>\node_modules\coffee-script\lib\coffee-script\register.js:45:36)
>>   at Function.Module._load (module.js:314:12)
>>   at Module.require (module.js:367:17)
>>   at require (internal/module.js:16:19)
>>   at loadTask (<my_project>\node_modules\grunt\lib\grunt\task.js:316:10)
>>   at <my_project>\node_modules\grunt\lib\grunt\task.js:354:7
>>   at Array.forEach (native)
>>   at loadTasks (<my_project>\node_modules\grunt\lib\grunt\task.js:353:11)
>>   at task.loadTasks (<my_project>\node_modules\grunt\lib\grunt\task.js:365:5)
>>   at Array.forEach (native)
>>   at Task.task.init (<my_project>\node_modules\grunt\lib\grunt\task.js:457:45)
>>   at Object.grunt.tasks (<my_project>\node_modules\grunt\lib\grunt.js:111:8)
>>   at Object.module.exports [as cli] (<my_project>\node_modules\grunt\lib\grunt\cli.js:27:9)
>>   at Object.<anonymous> (C:\Users\ME\AppData\Roaming\nvm\v5.6.0\node_modules\grunt-cli\bin\grunt:44:20)
>>   at Module._compile (module.js:413:34)
>>   at Object.Module._extensions..js (module.js:422:10)
>>   at Module.load (module.js:357:32)
>>   at Function.Module._load (module.js:314:12)
>>   at Function.Module.runMain (module.js:447:10)
>>   at startup (node.js:140:18)
>>   at node.js:1001:3

Running tasks: _intellij_grunt_tasks_fetcher
Warning: Task "_intellij_grunt_tasks_fetcher" not found. Use --force to continue.

Aborted due to warnings.

Googling with:

webstorm "failed to list tasks" gruntfile

...returns precisely zero results in English.

I am using nvm to manage multiple Node.js versions on my machine. I have seen other posts on SO mentioning some dodgy interactions with nvm in scenarios like this, but as best I can tell, I don't think those anecdotes apply in my situation, as I'm using Windows.

I've scoured the web on this one for several hours over the course of weeks, and tried a variety of things-- nothing seems to help.

via PattMauler