Don't fail if a file is created in an invalid directory

backend/main.go

@@ -87,7 +87,11 @@ func main() {
 				// Extract
 				spath := strings.Split(strings.TrimPrefix(ev.Name, SubmissionDir), "/")
 
-				go treatSubmission(ev.Name, spath[1], spath[2])
+				if len(spath) > 2 {
+					go treatSubmission(ev.Name, spath[1], spath[2])
+				} else {
+					log.Println("Invalid new file:", ev.Name)
+				}
 			}
 		case err := <-watcher.Error:
 			log.Println("error:", err)