I found my finished download stayed in the Unfinished folder with .dctmp extension. If I rename it to the original name and open it looks OK. How come?

When DC++ starts to download a file it'll create a temporary file in the Unfinished downloads folder for each download. The file size is equal to the size of the download and will be named like <filename>.<extension>.<TTH>.dctmp. The files stay in the Unfinished folder until the download finishes. Then they'll be moved to their target location (either to the Finished downloads folder or to the folder you specified if you used Download to...).

There are possible cases when the rename/move operation fails so the finished download left in the Unfinished downloads folder even if it has been finished :

1. The disk is full in the target location
2. DC++ does not have sufficient rights to write access the target folder
3. DC++ is closed or crashed when the download finished or during the move operation
4. The Finished and Unfinished Downloads points to the same folder or you set the Unfinished folder as the target location for a file =)
5. A file with the same name as the download exists in the target folder and it is opened with another application during the move operation
6. Any other problem which keeps DC++ from move the file to the target successfully (invalid path set for finished downloads, file system corruption, detached removable device, disconected network connection, etc...)