getting error while building kickstart project .

[srv smn]

while running npm run build in kickstart project , I am getting error

Failed to build on C:\Users\SOURAV~1\AppData\Local\Temp\53b6d83f-30ac-4b07-91c9-0cc0bef8f857 Error: commons.js from UglifyJs Unexpected token keyword «function», expected punc «,» [commons.js:31221,28] at F:\EthereumCasts\kickstart\node_modules\next\dist\server\build\index.js:182:21 at F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:269:13 at Compiler.emitRecords (F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:375:38) at F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:262:10 at F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:368:12 at next (F:\EthereumCasts\kickstart\node_modules\tapable\lib\Tapable.js:218:11) at Compiler.<anonymous> (F:\EthereumCasts\kickstart\node_modules\webpack\lib\performance\SizeLimitsPlugin.js:99:4) at Compiler.applyPluginsAsyncSeries1 (F:\EthereumCasts\kickstart\node_modules\tapable\lib\Tapable.js:222:13) at Compiler.afterEmit (F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:365:9) at F:\EthereumCasts\kickstart\node_modules\webpack\lib\Compiler.js:354:15 { errors: [ 'commons.js from UglifyJs\n' + 'Unexpected token keyword «function», expected punc «,» [commons.js:31221,28]' ], warnings: [] } npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! kickstart@1.0.0 build:next build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the kickstart@1.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Sourav Suman\AppData\Roaming\npm-cache_logs\2020-04-26T03_15_14_433Z-debug.log`