I have Basecamp version 4.6.2 and have been using it for years. I fear to update to the latest 4.6.5 for loss of features or other issues. Today my fears came true.
Using Garmin Express, I updated maps on my Garmin GPS and had it also updated the maps on the PC or for the Basecamp app, at the same time. Somehow, during this procedure, Basecamp got updated to 4.6.5 and I only noticed because most of my extensive Basecamp Library was now gone. As the Basecamp onboard backup is only manual, I easily forget to back it up and my current backup was a couple of months old. Luckily, I back up my entire PC drives each day, and from those backups I restored the entire Basecamp folder on the PC from a few days prior, and the Basecamp was restored to 4.6.2 and the entire Library was recovered.