blank costumes

Please fill out these questions for all feature requests and bug reports. If you're requesting a feature, please let us know why this feature is important or useful, not just what it should do.
Thanks!

  1. What browsers show this problem? Chrome
  2. Please share an example project (if possible). snap.berkeley.edu/snap/snap.html#present:Username=SnapenilK&ProjectName=Baffoozling&editMode&noRun
  3. Describes the steps to reproduce this issue. I don't know how it happened. It reminds me of what happened to a lot of my sounds in Scratch.
  4. What does Snap! currently do? speaker's off costume and both of brick wall's costumes have suddenly become blank
  5. What should Snap! do instead? Keep the costumes

Is this bug a security concern? If so, please do not post security concerns directly to the forum. Please email us at contact@snap.berkeley.edu. Thank you!

I think I know how to get them back without redrawing them or erasing new things: save what I have so far, recover it, save it as a new project, download the recovered costumes, open the current version of the project, and import the downloaded images.

Save what I have so far; done.
Recover it; done.
Save it as a new project; unnecessary.
Download the recovered costumes; done.
Open the current version of the project; error:

Well, I reloaded the page and I didn't get the null error again.