Hi ​@poloem, 

Welcome to Box Community, and we’re glad to assist with your upload issue. 

Even though your account shows 0 B used (and a 10 GB allotment), Box can still block uploads when the owner of the target folder (not necessarily you) has reached their storage quota — or when the displayed storage numbers are temporarily out of sync. The fix depends on which of those is happening.

In this case, please identify the target folder and reach out to its folder owner. 

Thanks for posting, and if you have additional questions please reply in this thread. 

Hello,

The information about the folder owner's quota being the issue makes perfect sense, and I appreciate you pointing out that this can happen even when my own storage looks fine. I'll reach out to the folder owner right away. This was very helpful!