We’ve been seeing more reports of this lately, sorry this happened to your condo. There isn’t really anything we can do if your local data is lost like this if there isn’t a backup, best I can do is share our thoughts on the issue what we’re doing to mitigate this in the future.
Previously we thought it was purely an issue with steam’s cloud saves which had put a fix out of reach for us, but recent reports point to it actually being an issue with steam’s inventory system going out during loading. If we can detect the inventory system going down we might be able to put a work around for this to prevent this problem in the future. We’re also planning on starting work on an automated backup save system next week, which could take snapshots of the condo x days apart. It would probably be a small number of backups to keep disc size down, with an intent to add a setting to allow people to have more if they want.