I haven't used my space and I have much space but when using FileZilla to upload files, I get an error like this:

Command: STOR theme_info.cfg
Response: 552 Disk full - please upload later
Error: Critical file transfer error

I have limited knowledge on this FTP, Web-Hosting thing but I now can't upload.. WHY??

I have searched the forum but I can't get answer to my question.