Importer utility is not working to upload the scripts

[Lenin]

We recently installed the ZAPHYR for jira. i got a below error message when i try to upload the scripts ->

Mon Jul 31 11:00:22 BST 2017 file:///C:/Users/lenin.babu/Desktop/115.xlsx normalization success..! Mon Jul 31 11:00:22 BST 2017 Issue  created! Mon Jul 31 11:00:22 BST 2017 Unable to add testcase ending at rowNumber - 12. Error:Unexpected response code: 404 <?xml version="1.0" encoding="UTF-8" standalone="yes"?><status><status-code>404</status-code><message>null for uri: http://10.200.12.96:8010/rest/zephyr/latest/teststep/</message></status> Mon Jul 31 11:00:22 BST 2017 115.xlsx imported successfully..!