Here is some relevant information from the log file:
2025-08-23T11:07:27 MCEBuddy.AppWrapper.Base → Cleanup summary: 0 removed, 0 failed
2025-08-23T11:07:27 MCEBuddy.AppWrapper.Base → Cleaning up extracted subtitle files…
2025-08-23T11:07:27 MCEBuddy.AppWrapper.Base → Removed current instance marker: W:\Temp\VideoProcessing_Instances\convertHdr10+ToAV1.52988.marker
2025-08-23T11:07:27 MCEBuddy.AppWrapper.Base → Cleanup handlers unregistered
→ Process exited with code 1
2025-08-23T11:07:30 MCEBuddy.Engine.ConversionJob → Finished custom command, file size [KB] 62,040,758.00
INFORMATION> 2025-08-23T11:07:30 MCEBuddy.Engine.ConversionJob → Moving converted file to destination