Hi engconder,

thanks for reporting the issue. As you can read from the adapters.xml template available under DOCS-SDKs/adapter_generic_infrastructure/doc/adapter_conf_template or DOCS-SDKs/adapter_generic_infrastructure/doc/adapter_robust_conf_template of the Lightstreamer distribution, for Proxy Adapters it is also mandatory to specify the classloader both in the metadata_provider and in the data_provider configurations. In such case, as stated in the comment, it is advisable to use the special "log-enabled" option, as follows:
Code:
<metadata_provider>
  <adapter_class>PROXY_FOR_REMOTE_ADAPTER</adapter_class>
  <classloader>log-enabled</classloader>
  <param name="request_reply_port">6663</param>
</metadata_provider>
Code:
<data_provider name="DataPool">
  <adapter_class>PROXY_FOR_REMOTE_ADAPTER</adapter_class>
  <classloader>log-enabled</classloader>
  <param name="request_reply_port">6661</param>
  <param name="notify_port">6662</param>
</data_provider>>
Such configurations are required because of newly introduced Classloader separation in Lightstreamer 6.0: you can get more on this here.

For the sake of completeness, I have also modified the previous reply, inserting the same tag as above.

Get back to us for any further issue.

Regards,
Gianluca