HTML VIew: calendar-win2k-1.css Failed to load resource: the server responded with a status of 404 (Not Found)

HTML VIew: calendar-win2k-1.css Failed to load resource: the server responded with a status of 404 (Not Found)

I am trying to optimise the loading times in some of my HTML views and have come across an error that is not actually part of my specific HTML view but looks like it might be part of the html views in general.

This is not major, but should be addressed.

calendar-win2k-1.cssFailed to load resource: the server responded with a status of 404 (Not Found)
- When I look at the HTML view via Chrome Developer Tools, I find that it keeps trying to load this CSS file
- I had thought it was one I had linked to but it seems to be part of the html view code

Thought I would put the issue up here.
Thanks zoho crew - you all do an amazing job.