klode on "[Plugin: Google Analytics Dashboard for WP] Could not json decode the token"

Hi,
in my website it works fine, as on many other websites with the same version of WordPress.
But on http://klode.altervista.org I get this error:

<b>Fatal error</b>:  Uncaught exception 'Google_AuthException' with message 'Could not json decode the token' in /membri2/klode/wp-content/plugins/google-analytics-dashboard-for-wp/src/auth/Google_OAuth2.php:153
Stack trace:
#0 /membri2/klode/wp-content/plugins/google-analytics-dashboard-for-wp/src/auth/Google_OAuth2.php(104): Google_OAuth2->setAccessToken('Protection: 1; ...')
#1 /membri2/klode/wp-content/plugins/google-analytics-dashboard-for-wp/src/Google_Client.php(131): Google_OAuth2->authenticate(Array, '4/ewERQTDvMRcIO...')
#2 /membri2/klode/wp-content/plugins/google-analytics-dashboard-for-wp/ga_dash.php(339): Google_Client->authenticate('4/ewERQTDvMRcIO...')
#3 [internal function]: ga_dash_content('', Array)
#4 /membri2/klode/wp-admin/includes/template.php(925): call_user_func('ga_dash_content', '', Array)
#5 /membri2/klode/wp-admin/includes/dashboard.php(204): do_meta_boxes('dashboard', 'normal', '')
#6 /membri2/klode/wp-admin/index.php(129): wp_dashboard()
#7 {main}
  thrown in <b>/membri2/klode/wp-content/plugins/google-analytics-dashboard-for-wp/src/auth/Google_OAuth2.php</b> on line <b>153</b><br />

Infact I get this JSON string (it's not a real JSON string!):

Protection: 1; mode=block
Server: GSE
Alternate-Protocol: 443:quic
Transfer-Encoding: chunked

{
  "access_token" : [redacted],
  "token_type" : "Bearer",
  "expires_in" : 3600,
  "refresh_token" : [redacted]
}

How can I resolve this issue?

http://wordpress.org/plugins/google-analytics-dashboard-for-wp/