The npm blog has been discontinued.
Error code EPUBLISHCONFLICT and "cannot publish over existing version"
When we moved to our more reliable, distributed architecture, we unfortunately introduced an unavoidable race condition that affects users attempting to publish modules using versions of npm prior to 1.3.21 (which means Node.js prior to version 10.24). This effect is particularly evident if your internet connection is slow, or if you are physically far away from our servers in North America.
We have tried to mitigate this condition at the server side, but if you are persistently getting this error, the fix is simple: update npm. Just run
npm install npm -g
And your publishing woes will be over. Our apologies!
(If you are not sure what version of npm you have,
npm --version will tell you, but in general upgrading is a good idea no matter what version you’re on)