Hi @Anonymous ,
This issue might caused by slow Internet connection. You can use registry to improve. Please refer to following command.
npm config set registry https://registry.npm.taobao.org
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update--------------------------
I installed node.14.7.0 and run the following cmdlet
md spfx-webpart
cd spfx-webpart
npm install gulp-cli yo @microsoft/generator-sharepoint --global
Then I stuck at rollbackFailedOptional: verb npm-session for a long time. Finally it run again and installed success.
The process take me about 40 minutes
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