New error/warning message after update

I just updated npm and now when I load the Meteor app the first message I see in the terminal is:

Building for web.browser -
Replace Autoprefixer browsers option to Browserslist config.
Use browserslist key in package.json or .browserslistrc file.

Using browsers option cause some error. Browserslist config
can be used for Babel, Autoprefixer, postcss-normalize and other tools.

If you really need to use option, rename it to overrideBrowserslist.

Learn more at:

Not sure how to fix this. Any help appreciated.

I never saw this error, but you can try delete .meteor folder (remember that your mongodb data are in this folder too).

Or you can delete all meteor installation files and npm files in your computer. When you start you app again, meteor download everything again. Maybe works.