Low storage limit for a Site Collection
I have KanBo installed and I get an email from Microsoft about my Site Collection's storage limit. What can be wrong?
Your site collection is approaching its storage limit. It's not a problem yet, but if you run out of storage space, any changes you make won't be saved.
To free up space:Go to https://yourkanbourl.sharepoint.com
Select the files you want to delete.
Empty the recycle bin
Please change your Storage Quota in https://yourkanbourl-admin.sharepoint.com/_layouts/15/online/SiteCollections.aspx