REST API scripts are not working-automation not working after upgrade to 17.x

There were several security improvements done in the REST API between v15 and v17, including that it used to accept anonymous local requests. It's likely that the script you're using was developed for v15 and no longer work on v17. 

Can you share the exact process you're following that results in the failure, including where the scripts are that you're using? We'd need enough information to to reproduce the issue and make an update to wherever the script came from.