I recently had to factory reset my PC because of some registry issues, but when I logged back in to Adobe Digital Editions, I found that all of my textbooks I had on the account had vanished.
I don't know why this would happen, and I'm honestly disappointed with the functionality of Adobe Digital Editions. Given that everything is cloud-based nowadays, being able to log in to your account and view books you own should not be a problem.
Nonetheless, I hope there is a solution.
The eBook are solved on the local disc. If you restart your System the files are seems are remove. The Cloud syncro at moment only work from mobiel version to device version. Not save the eBooks on the Cloud for a other PC.