What does the Upgrade warning mean?
The Upgrade warning appears in the Main toolbar when you are close to the space limit in your Koofr account. If you click on the Upgrade warning you will see a message: "Your account is almost full. Why not upgrade?" in case you still have some space left in your account or "Whoooaaaa. You sure seem to have a lot of files. Your storage in full and new files cannot be uploaded. Why not upgrade?" if there is no space left or you are already over quota. If the latter is the case, you will need to buy more space on Koofr if you want to be able to upload new files. After a period of time, you will be warned that your over-quota files will be removed unless you upgrade your account or remove the files yourself.