puppeteer TypeError: text is not iterable

(node:9828) UnhandledPromiseRejectionWarning: TypeError: text is not iterable
    at Keyboard.type (D:\workspace\auto-ui\node_modules\puppeteer-core\lib\Input.js:160:24)
    at Keyboard.<anonymous> (D:\workspace\auto-ui\node_modules\puppeteer-core\lib\helper.js:112:23)
    at openBrowser (D:\workspace\auto-ui\test-email\index.js:106:25)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:9828) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 3)
(node:9828) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.