i found out the hard way that Dropbox is not a storage site to be relied upon as your only backup. Sadly I learned the hard way. I retired in early 2019 and was doing a lot of consulting work with former suppliers. In many cases files i had stored on DropBox from 40 years of Engineering made things pretty easy for me to help them. Covid hit the consulting work stopped. Fast forward over a year. It seems that there is an activity time clock and if you do not access your drop box in that time Dropbox decides you obviously do not need the files stored on the site any longer. Not once did i receive a mail indicating that i was about to lose all my data and files. Covid has lightened up and things are opening up some, including requests for my consulting. The first time i accessed DropBox to retrieve a file that would have helped my customer, imagine my surprise to find ABSOLUTELY ZERO FILES IN MY DRIVE! This cost me hours of unnecessary research to duplicate what i already had in Dropbox. I also lost hundreds of pictures, fortunately i was able to get just over half of those back from the original sources. The rest are out in the ethos! To all I would suggest an alternate back up location to preserve anything you deem important.