org.eclipse.gemini.blueprint.service.importer.ServiceProxyDestroyedException: service proxy has been destroyed

Hi,
I created plugin with custom rest API, which return data from active objects’entities. It works well on Test instance. Plugin was installed on Prod instance.

At first, about a month, there were no problems. Now it works strange: for some days it also works well, but then all custom API begin to return error “org.eclipse.gemini.blueprint.service.importer.ServiceProxyDestroyedException: service proxy has been destroyed”. It shows, that there is error in code with active obects’entity call.

Example:
SettingResource.java

@Path("settings")
@Produces({MediaType.APPLICATION_JSON})
public classSettingsResource {
    @GET
    @Produces({MediaType.APPLICATION_JSON})
    public Response getSettings() throws Exception {
    
        List<XmlSettings> xmlSettings = Lists.newArrayList();
        for (SettingsEntity entity : AOFactory.getInstance().getSettingsAO().getSettings() {
  
            xmlSettings.add(SettingsMapper.toXmlSettings(entity));
        }
        return Response.ok(xmlSettings).build();
    }
}

SettingsAOIMpl.java

public class SettingsAOIMpl implements SettingsAO { 
    
    private final ActiveObjects ao;

    public SettingsAOIMpl(ActiveObjects ao) {
        this.ao = ao;
    }
    public SettingsEntity[] getSettings() throws Exception {
        return ao.executeInTransaction(new TransactionCallback<SettingsEntity[]) {
            @Override
            public SettingsEntity[] doInTransaction() {
                return ao.find(Settings.class, Query.select());
            }
        });
    }
}

Rest API returns error SettingsAOIMp.getSettings.

If I reinstall plugin, It works well for some days again and then error returns.

How can I solve the problem? How to check connection with Active objects?
And how to restore this connection if it fail?