All files suddenly missing

Hi there, 

Welcome to Box Community and glad to help!  

Do you know if these are your collaborated folders? If so, you may reach out to the owner to gain back your access to these folders. 

Meanwhile, if you own these missing contents, please go over to your trash and locate your missing files. You can filter content by items you own, or by items you’ve deleted.  To do this, directly beneath the folder label (Trash), click the Items I Own (or Items I Deleted) down arrow.  Then click the option you want.

Once you have located the missing files, here's how you could restore it: 

The steps below apply whether you’re selecting from search results or from all Trash items.

1. Hover to highlight the row of the item you want. The More Options ellipsis (…) displays.
2. Click the ellipsis (...).  Then: 

• To return the item to its original location in Box, click Restore.

3. At the prompt, click Okay.

Hope it helps!