Multiple times now I’ve had to engage in needlessly complicated workarounds because (I assume) the asset library is aggressively cached. I uploaded one bad asset that I had improperly converted and it was nearly impossible to overwrite it. As I’m writing this, there’s one asset in my library that is utterly impossible to overwrite. Delete the file and upload a new one and it revives the old one. Upload a file with a different name and rename it? Revives the old one.
I’ve been trying to update a single asset for half an hour now. I am frankly astonished that this service cannot handle basic asset management.
Hello there!
While the asset library supports renaming, it should also be understood that the CDN asks your browser to cache the asset for a lengthy time period.
Your issue may be solved by simply opening the asset url from your Foundry file picker in a new browser tab and hitting CTRL+F5 (or CMD if mac, I think). Which will force it to ignore the local cache.
Mind you, the browser doesn’t understand that the url assets.forge-vtt.com/something/something.png is the same as assets.forge-vtt.com/something/something.png?optimizer=disabled, so if you were to open it from the assets library, the url isn’t the same as from ingame.
Additionally, the modern web where everything is cached isn’t really built up for constantly changing the contents of a url, especially in situations where it goes through a CDN, which is optimized to delivery the same asset all over the world.
So your best and most sure fire way to immediately see results is to simply give it a new name.
I hope this helps, let us know how it goes.
Also don’t be afraid to join our discord for live assistance from our friendly moderators.
I’ll also add, the caching is probably not the issue here.
Most times, it is because Foundry hasn’t been restarted. (stop, start), as it saves it till it stops.
If you try uploading and stuff while Foundry isn’t on, it should take mere seconds before it replaces, if it has the same name.
Hopefully, this would be the issue, and you could move on with that 
I’m not sure why a restart would help.
Obviously you would reload the page at a bare minimum to get the new image, but a server restart makes no difference.
Try it
It’s usually how we/I’ve fixed these issues.