We have an archived folder called HeadlessChrome 77.0.3865 (Linux 0.0.0) with a file index.html the contents of that folder fail when served via resource root.
If I make a copy of the folder HeadlessChrome-77.0.3865-(Linux-0.0.0), that index.html file will be served successfully.

Pipeline for testing:

node('master') {
   sh '''mkdir -p "a/foo bar has lots of spaces to make people unhappy"
   touch "a/foo bar has lots of spaces to make people unhappy/index.html"
   '''
   archiveArtifacts 'a/'
}