Hi Milan,
Please ensure the integration is using PKI in Catalog under Administration > Configuration > CA Service Desk and confirm the 'Test' returns successful. For this you will need a valid web service policy in SDM,
Steps to configure the PKI:
1) In Service Desk verify the CASM_Policy web service policy exists (Administration > SOAP Web Services Policy > Policies) and:
a) 'Allow Impersonate' is selected
b) There is a valid proxy contact
2) Create CASM_POLICY.P12 by running 'pdm_pki -p CASM_POLICY -f'
3) Copy the generated CASM_POLICY.P12 to %USM_HOME% of each Catalog server in the environment
4) From Administration > Configuration > CA Service Desk set 'Enable PKI' to 'Yes' and ensure the 'Keystore Name' and 'Policy Code' are defined as 'CASM_POLICY' (case sensitive).
Thanks,
Jason