npm throws error on never published version

[Havvy]

error Plugin-JSHelp Error
error Plugin-JSHelp Error: 404 Not Found: sweet-assert
    at RegClient.<anonymous> (/home/havvy/heartless/node_modules/tennu-jshelp/node_modules/npm/node_modules/npm-registry-client/lib/request.js:309:14)
    at Request._callback (/home/havvy/heartless/node_modules/tennu-jshelp/node_modules/npm/node_modules/npm-registry-client/lib/request.js:251:65)
    at Request.self.callback (/home/havvy/heartless/node_modules/tennu-jshelp/node_modules/npm/node_modules/request/request.js:123:22)
    at Request.emit (events.js:98:17)
    at Request.<anonymous> (/home/havvy/heartless/node_modules/tennu-jshelp/node_modules/npm/node_modules/request/request.js:893:14)
    at Request.emit (events.js:117:20)
    at IncomingMessage.<anonymous> (/home/havvy/heartless/node_modules/tennu-jshelp/node_modules/npm/node_modules/request/request.js:844:12)
    at IncomingMessage.emit (events.js:117:20)
    at _stream_readable.js:943:16
    at process._tickDomainCallback (node.js:463:13)