Hi,
The message is quite hard to read in that format but hidden in there is the line To acknowledge the license, please read the following messages and update the license again, this time with the "acknowledge=true" parameter:"
Did you try curl -XPUT "http://x.x.x.x:9200/_xpack/license?acknowledge=true" -H "Content-Type: application/json" -d @license.json -u elastic