How to suppress Chrome DevTools warning: 'DevTools failed to load SourceMap: Could not load content for...'

Hide them via console filter like -/(load|parse)\sSourceMap/

^{(using a /regexp/ with \s seems to be the only working method of specifying strings with spaces)}

In DevTools (F12) -> Settings (F1) :

Disable both "enable JS source maps" and "enable CSS source maps" in "Preferences -> Sources"

If you open DevTools (F12) then look for the cog "Preferences" top/right you can disable "Enable JavaScript source maps" under the Sources section by un-checking that option.