The interface becomes annoyingly unreliable and unnecessarily confusing after thinking you have learned it. The interface appears to be friendly intuitive; however, it gets unpredictable and unreliable with changes. eg: There are times trying to retrieve items once confirmed in a folder, these items may or may no longer exist where they were once stored. Trying to delete the empty folder is a mysterious process. Using Dropbox is like rolling the dice. Sometimes everything works, and sometimes some features no longer work or get shifted. Using Dropbox is too unpredictable. In addition to customer service by BOTS, reported in many reviews, it seems that BOTS also handles software upgrades at random without warning to users or providing appropriate tutorials. That goes for paid and free accounts.Hey BOTS: STOP TRYING TO PACK SO MUCH UNTIL THE BASICS ARE OPERATING EFFICIENTLY. A four-year user's experience.