Hi Sara, Thanks for contacting us and sorry to hear that you’ve run into this issue! There isn’t any max file size or other limit that you’ve exceeded. It sounds like a Flash problem. I suggest exiting your web browser completely and then re-launching Ribbet. This should resolve the issue.
To ensure you don’t lose your work, first make sure you’re signed in, save your work, and then after re-launching Ribbet you will be able to find it on the Library > History tab.
Let us know if we can be of any further assistance!