diff --git a/certbot_dns_ionos/dns_ionos.py b/certbot_dns_ionos/dns_ionos.py
index a1c2dc0..2574c89 100644
--- a/certbot_dns_ionos/dns_ionos.py
+++ b/certbot_dns_ionos/dns_ionos.py
@@ -127,7 +127,7 @@ class _ionosClient(object):
             )
         logger.debug("API REquest to URL: %s", url)
         if resp.status_code != 200:
-            content = json.loads(resp.content)
+            content = json.loads(resp.content)[0] # on error content is array with 1 element
             error_msg = resp.reason + " " + content['message']
             raise errors.PluginError(
                 "HTTP Error during request {0}:{1}".format(resp.status_code, error_msg)