Help! Error on appinventor website corrupted my project!

[Taifun]

just import your lastest backup and restart from there
you have a backup? Great!
you do not have a backup? not so great...

see also

Back up your work with an aia file! By @Enis

This tip has been written by longterm power user @Enis. As his webpage soon might go away, I think, it is in his sense if we rescue the most important part of his tips for App Inventor here in the community. App Inventor is a cloud-based Android development environment. MIT has provided a simple way to back up your work, which you should do on a REGULAR basis. To backup your project, you export it to an AIA file that gets stored on your computer. Now, you may think it isn’t important, or that …

Taifun