Troubleshooting Tip : ZTNA TAG not resolving in FortiGate from EMS 'Error: http code 500'

If it has been found that the ZTNA tags are not resolving in FortiGate the first step is to verify the connection with EMS and check with the EMS debug. The following article shows the troubleshooting steps to check and verify the connection with EMS with debug commands: Troubleshooting Tip: Troubleshooting FortiGate with EMS

After running the 'diagnose debug application fcnacd -1' debug the report may show the following result.

2025-01-02 10:04:20 [_update_obj_stats:336] Storing (9, default.forti-ems.moto-profil.pl, 17)
2025-01-02 10:04:20 [ec_ez_worker_process:426] Call completed with failure.
obj-id: 9, desc: "REST API to get updates about vulnerabilities.", entry: "api/v1/report/fct/vuln".
error info: Error (-1@ec_ems_rest_api_preprocess_result:67). Error: http code 500. (fcems_report_preprocess,307)Issue in pre-processing the result (_vuln_report_pr
ocess_result,773)

If the HTTP error code 500 appears it means when FortiGate submits the API calls from FortiOS to EMS the call is completed with the mentioned error code and the API calls failed. This means the server cannot fulfill the API request initiated by FortiGate. 

The primary step is to reboot the EMS console and if the reboot does not resolve the issue it is requested to open a ticket to the TAC with the FortiClient EMS serial number.

Related articles:
Technical Tip: How to check the resolved addresses of ZTNA Tags in FortiGate
Technical Tip: How to add EMS in fabric connector with FortiGate API Access Key