You've run into one of the limits of a free account. When you moved from Yahoo! Photos, you were given a free trial of Flickr pro - our premium account that comes with unlimited storage and uploads. But, that's expired.

If you are ready, you can purchase pro for just $24.95 a year. To be sure, none of your uploads have been deleted, and they'll all come back after you upgrade.

If you aren't sure yet, don't worry. You'll simply continue on Flickr's free service, which is subject to a few limits, the main one being that it will only show the most recent 200 items you've uploaded. To see older stuff, you can delete some recent items. You can download them first if you like.