when i follow the guide to download the MDB Angular Mobile, open the app and run following commandnpm installtns preview

it shows me below errors.Unhandled rejection Error: invalid config key requested: error@2.1.8 extracted at BadKeyError (C:\Program Files\nodejs\node_modules\npm\node_modules\figgy-pudding\index.js:93:23) at pudGet (C:\Program Files\nodejs\node_modules\npm\node_modules\figgy-pudding\index.js:101:5) at FiggyPudding.get (C:\Program Files\nodejs\node_modules\npm\node_modules\figgy-pudding\index.js:27:12) at Object.get (C:\Program Files\nodejs\node_modules\npm\node_modules\figgy-pudding\index.js:159:16) at Object.checkData (C:\Program Files\nodejs\node_modules\npm\node_modules\ssri\index.js:232:22) at write (C:\Program Files\nodejs\node_modules\npm\node_modules\cacache\lib\content\write.js:34:31) at putData (C:\Program Files\nodejs\node_modules\npm\node_modules\cacache\put.js:29:10) at Object.x.put (C:\Program Files\nodejs\node_modules\npm\node_modules\cacache\locales\en.js:28:37) at readFileAsync.then.data (C:\Program Files\nodejs\node_modules\npm\node_modules\pacote\lib\fetchers\file.js:38:28) at tryCatcher (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\util.js:16:23) at Promise._settlePromiseFromHandler (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:512:31) at Promise._settlePromise (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:569:18) at Promise._settlePromise0 (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:614:10) at Promise._settlePromises (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:693:18) at Promise._fulfill (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:638:18) at C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\nodeback.js:42:21

npm ERR! cb() never called!

npm ERR! This is an error with npm itself. Please report this error at:npm ERR! https://npm.community

npm ERR! A complete log of this run can be found in:npm ERR! C:\Users\Administrator\AppData\Roaming\npm-cache_logs\2019-11-20T05_50_58_284Z-debug.logCommand npm.cmd failed with exit code 1