Lost NPCs and Monster Stat Blocks!!!!

So I got on to do some prep work for my game Sunday, and when I started loading in a map I looked over my quests/ quest NPCS. They were all gone! I was like, strange.... I created them myself. So, I went to another folder of Monster stat blocks and Exotic mount stat blocks I had added over time and discovered the folders were ALL EMPTY! I then thought, hey maybe a glitch happened so I reloaded the game and still they weren't there. I don't understand when it could have happened over the last 3-4 days but somehow they just got dumped? I checked and my quest handouts are still in the game but just not monster/npc stat blocks. Even my players characters are still there. So, I rolled back the game to the day of the last game and everything returned. However, now my players have to REDO their 7th Level stuff again and I have to go over everything from the last session to double check what was lost. What caused this and how can I prevent it from happening in the future?

Hi Dustin,  Is this a regular game or Jumpgate? Would you happen to be using Better20's import tool?

If you install the Inspector script, you can poke around and see what scripts see in your game. IoW, it could tell you if the characters are still there and you're just failing to see/find them. You could browse through all characters by starting with this command: !inspect --type character ...or you could look for a specific missing character with this command: !inspect --Character Name

Refresh your page. I just had the same issue and was about to post my own topic when I went back into my game and the statblocks appeared in the folders where I put them.

Hi Everyone,  The Devs have posted a response to this issue  here . Please post future thread posts on this topic in that thread so we can keep it to one thread. 

Hey everyone affected by this, the Devs have pushed a new post . Please go read it and if you need further help follow the directions. Short version: an extension was not the cause, Roll20 found the root cause. They are offering rollbacks to anyone that needs one but due to how rollbacks work there is a limited timeframe for that (7days).