It looks like it might be failing due to an OpenCL problem (used for hardware accelerated HDR tone mapping):
Apr 20, 2024 22:01:01.709 [124543653915448] ERROR - [Req#b01/Transcode/A9AEDEFC-1A9D-426A-BD40-161F93FD3312/8383a71b-a648-4409-a3b3-a63bf0226106] [AVHWDeviceContext @ 0x774bf78d1b00] Failed to get number of OpenCL platforms: -1001.
Do you have HDR tone mapping enabled in your server’s transcoder settings? If so, try disabling that and see if HW acceleration of AV1 works then.
[Edit]
If it ends up working with HDR tone mapping off, here’s another thread to follow which discusses that particular problem (HW accelerated transcoding failing when HDR tone mapping is enabled):
