Image path containing space not being found

Theres an image on the homepage of my site with the path:

/Images/Advert/advert one.jpg

This has been displaying on the page in the last week, but now the image cannot be found. I've checked the location, and its not been removed. I simply changed the path to:

/Images/Advert/advert-one.jpg

And now the image is f开发者_高级运维ound! Why does having a space in the path prevent the browser from finding it?

There are people other than myself who have access to the server, so its possible they have changed a setting, although they believe they haven't, and furthermore I didn't realise such a setting would exist?

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URLs cant contain a space. Try replacing the space with %20, e.g. /Images/Advert/advert%20one.jpg