When I go ahead and try the experimental hardware folder, the problem is that VAAPI AMD H264 AND VAAPI Intel H264 are not supported. I’m running Windows 10.
Looks like you have an Nvidia graphics card (NVENC is the profile for Nvidia cards, VAAPI AMD for Radeon cards, and VAAPI Intel for onboard Intel cards).
You may want to run the Config Wizard from Menu > Settings to have Kdenlive select the correct settings for your HW