If Nero Recode pops up "The RPC server is unavailable" error when converting files, would you please try below steps?.
1. Unselect "Hardware acceleration" in Recode settings, then start encoding, can it work?
2. If yes, this may be due to your display adapter driver out of date, please update to the latest version from the official website:
- Geforce Nvida display adapter: https://www.nvidia.com/Download/index.aspx?lang=en
- AMD display adapter: https://www.amd.com/en/support
- Intel display adapter: https://downloadcenter.intel.com/product/80939/-
Then check if converting works.