If there is a existing file new.png, the device automatically adds a (1) to the file, e.g here: new(1).png. What is the returned file Name in the Download Complete event? The given Save File As or the created file name existing in the device?
Checks whether a file or directory exists.
Prefix the filename with / (i.e. relative path) to look for the file on the SD card. For instance /myFile.txt will look for the file /mnt/sdcard/myFile.txt. To read assets packaged with an application (also works for the Companion) start the filename with // (two slashes). If a fileOrDirectoryName starts with file:/// you can specify a complete path to the file of directory."
Taifun Extention link here