I was working on a R script. The moment I saved the file and quit RStudio, the script file which is synced in a dropbox folder is turned to a 0 byte file. When I tried to open the file from dropbox web, it showed me "Error (415)". When I tried to recover it from the "version history" option, I found that strangely there are no previously saved versions though I saved it many times during my code writing and trail running. I also searched in my computer's recycle bin and dropbox's deleted file section. There is nothing. How can I recover it? It is an important file.