The code.appinventor server frequently glitches. It is glitched at the moment until MIT resets it.
I recommend users of this server always back up their Projects with an aia file at times like this. It will help reduce developer's stress levels when something like this happens.
The server has NOT been like this for months Brian. It is generally up and running.
When using code... some of the project size restrictions are not present versus the main ai2 server.. Code... doesn't have the "deadline" limits and other limits imposed by App Engine.
Keep in mind that the ultimate limit on how big an App you can make will be the memory consumed by your browser. If you are continually having issues, you may be reaching the practicl size limits for App Inventor 2.
Try again later today Brian. MIT has been informed.
Regards,
Steve