Discovering by VMware VIM Protocol

Hello folks
I am unable to discover VMware infostructure using VMware VIM Protocol.
So far I did and checked following:
- User with required rights was created on VSphere
- I am able to reach https://< ip VmWare >/sdk/vimService.wsdl
- I have imported required VmWare SDK *.jar files into uCMDB

When I run the "Check Credential" I get the following:

Failed to get credential 19_1_CMS, please check the related error logs in probe side.

When I run "Manual VMware VIM Connection" discovery module I get the following error:

<< Progress message, Severity: Error>>
Failed executing script, details: Traceback (most recent call last):
  File "<string>", line 2, in <module>
  File "vmware_vim_connection_manual", line 42, in DiscoveryMain
  File "vmware_vim", line 401, in initConnectionConfigurations
  File "vmware_vim", line 281, in generate
    at java.util.Hashtable.containsKey(
    at com.hp.ucmdb.discovery.library.credentials.dictionary.NonSecureProtocolDictionaryManager.getProtocolById(
    at com.hp.ucmdb.discovery.library.credentials.dictionary.ProtocolDictionaryManager.getProtocolById(
    at com.hp.ucmdb.discovery.library.credentials.dictionary.ProtocolDictionaryManager.getProtocolProperty(
    at com.hp.ucmdb.discovery.library.clients.ClientsFrameworkImpl.getProtocolProperty(
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(
    at java.lang.reflect.Method.invoke(
java.lang.NullPointerException: java.lang.NullPointerException

Can one help what to check next or how to troubleshoot this.