Why did we get a notice to upgrade our account?

Why am i getting a notice of "out of storage limit" ? I checked my submissions and storage and they are all good.

Apologies for any inconveniences  i have checked your account and seems to be in good health. Seems to be a cache issues or glitch in the system however I can confirm you account is is good health and you can disregard the notification.

I have noted that it has also disappeared when i access your account. You may consider clearing your browser cache and access your account again.

Clear browser cache guide: https://kb.iu.edu/d/ahic