Hi Jennifer,
please note the you can also use the feedback form in yEd Live (e.g. in the application header on the top right corner, or via "Menu" -> "Feedback") to contact us directly from within the application.
Nevertheless, thank you for pointing this out. I have seen this once in the past but assumed that it was just some weirdness of my client system.
I noticed that this only happens for older files and I was not able to find the actual root cause to this.
You can workaround this by downloading the file through the Google Drive UI (e.g. open it in a separate browser window) and then load it in yEd Live again.
Then, if you export it to Google Drive again (from within yEd Live), loading from Google Drive seems to work again.
I will create a ticket in our internal issue tracker since it does not seem to be a one-time incident anymore.
- Fabian