Trying to run kdenlive.exe on Windows 8.1 was silently failing (no UI error messages, etc). Turns out my antivirus (Avast!) was flagging one of the kdenlive files as a false positive (kioslave.exe) and I needed to add an exception through Avast!’s Virus Chest interface.
This issue was in relation to Kdenlive 18.08.1.
