Checking if a user is subbed to my Channel returns Exception

[mircoianese]

Hi. I'm trying to make a method to return whether a user is subbed to my channel or not.
I have authenticated my channel with the CHANNEL_SUBSCRIPTIONS Scope but, when I try to handle the getSubscription response I get an Exception:

com.fasterxml.jackson.core.JsonParseException: Illegal character ((CTRL-CHAR, code 31)): only regular white space (\r, \n, \t) is allowed between tokens
 at [Source: �����ڍY���1��0��������8��}@cI%ZPh�4�]o���L
G�%����M	�z��9�C��,��3�kҍ�X��s�5(�Β��ll���=���������1��AY���; line: 1, column: 2]

Here's the code:

twitch.channels().getSubscription("myChannelName", "UserToCheck", new ChannelSubscriptionResponseHandler() {
            
            @Override
            public void onSuccess(ChannelSubscription channelSubscription) {
                return true;
            }

            @Override
            public void onFailure(int i, String s, String s1) {
               return false;
            }

            @Override
            public void onFailure(Throwable throwable) {
            	System.out.println( throwable);
                return false;
            }
});

So I get into the onFailure(Throwable throwable) method. What I'm doing wrong?
Thank you!