Simulink Webview Missing Gregorian.js

I am using the "slwebview" command to generate HTML pages for models. I have used it on a handful of models without issue, but for one model in particular slwebview runs successfully only to fail in the browser. The page tries to load "support/lib/dojo/cldr/nls/gregorian.js" which does not seem to exist in the output. The file doesn't appear in any only model's HTML files that I've found.