Files got deleted without reason and can not be restored

[Herb_Taiwan]

Help !

It just happened around 11:50 (GMT +eight, July 30), after I opened and closed an Excell file, this file disappeared without any reason !

Then I went to Dropbox Website to check "Deleted Files", it was there (but marked "deledted 1 hour ago, strange, it was actually just 5 minutes ago ), so I restored it, shows restored successfully, but nothing there, event not in "Deleted Files" area.

1 hour after, it showed in the " Deleted Files" area again. This time I turned off the old PC and used another PC without dropbox client program and visited dropbox website again to resotred the file, still,  shows restored successfully, but nothing there, , event not in "Deleted Files" area.

I did another test to open another excell file in my old PC (which has dropbox client program) and closed it. the same thing happened, the second file disappeared, and the same story above.

It's so so scaring, anyone can help ?

[Herb_Taiwan · Accepted solution]

Now solved. I don't know why, just found the lost 2 files in "Deleted Files" again after 1 hour, and restored them again.

This time they can show in their original path.

Supplementary:

When I came back home after work I realized what happened. the above story I had in my office, and the same time my son was using computer home which has dropbox client program. He and home computer got virus showing a skull icon ........

This virus kept killing all the newly updated Excell files in some dropbox subfolder, I tried, only Excell files , only newly updated ones, and only in that folder. Anyway I reinstall the whole Win 10 and solved it.