Hi Carla,
Sorry for the slow reply. From your post but it sounds like you may have accidentally overwritten your file.
Here’s a potential route to recover the version of the file before this all happened.
Sign-in to Trimble Connect at connect.trimble.com. This is the service SketchUp uses to save your models and also create a version history.
Navigate to your file. It may be in the ‘SketchUp’ project folder, or another project if you’ve created another project.
Click the checkbox next the name of your file. Don’t click on the name itself. (This will show you that error message you quoted above) See the attached image below:
In the right-hand nav, click on the far right icon. This will show you a version history. Scan back to find a version of the file before your over-write disaster.
Click the ‘cloud download icon’. This will pull down the SKP file for your recovered file. From here, you can upload this file back into SketchUp for Web and either save it as a new file, or Save As to overwrite the blank file you are trying to recover.
This image should help!
Let me know if this helps you get back up and running!
Mark
PS No need to submit an enhancement request: we know this is a confusing problem to run into!