There is similar error log “Error starting userland proxy: listen tcp4 0.0.0.0:8888: bind: address already in use”) " in topic Faster_RCNN sample dataset_convert command raise 'Docker instantiation failed with error: 500 Server Error: Internal Server Error'
Please change the Ports section in the ~/.tao_mounts.json from 8888 to 8889 and retry.
Refer to