diff --git a/src/brewserverblocklist/brewserverblocklist.py b/src/brewserverblocklist/brewserverblocklist.py
index 56f6d8f..633e17a 100644
--- a/src/brewserverblocklist/brewserverblocklist.py
+++ b/src/brewserverblocklist/brewserverblocklist.py
@@ -32,6 +32,7 @@ class BrewBlocklist():
         self.auto_accept = auto_accept
         self.auto_accept_direction = auto_accept_direction
         self.safe_harbor = []
+        self.error = []
         config = configparser.RawConfigParser()
         config.read(configfile)
         for section in config.sections():
@@ -62,6 +63,9 @@ class BrewBlocklist():
             if source['type'] == 'friendica':
                 # Friendica publishes the blocklist as CSV file
                 requ = requests.get('https://{}/blocklist/domain/download'.format(source['url']))
+                if not requ.status_code == requests.codes.ok:
+                    self.error.append('The request to {} failed'.format(sources['url']))
+                    break
                 for line in requ.text.split('\n'):
                     try:
                         pattern, reason = line.split(',')
@@ -75,9 +79,15 @@ class BrewBlocklist():
             elif source['type'] == 'mastodon':
                 # Mastodon has an API endpoint that contains the information
                 requ = requests.get('https://{}//api/v1/instance/domain_blocks'.format(source['url']))
-                for item in requ.json():
-                    self.blocklist[item['domain']] = self.blocklist.get(item['domain'], 0) + source['trust']
-                    self.reasons[item['domain']] = self.reasons.get(item['domain'], item['comment'])
+                if not requ.status_code == requests.codes.ok:
+                    self.error.append('The request to {} failed'.format(sources['url']))
+                    break
+                try:
+                    for item in requ.json():
+                        self.blocklist[item['domain']] = self.blocklist.get(item['domain'], 0) + source['trust']
+                        self.reasons[item['domain']] = self.reasons.get(item['domain'], item['comment'])
+                except:
+                    self.error.append('{} returned no valid json to the API call'.format(source['url']))
             else:
                 raise ValueError('{} is not a supported node type, check your config file'.format(source['type']))
 
@@ -129,6 +139,9 @@ class BrewBlocklist():
         if self.outputfile:
             sys.stdout = orig_stdout
             out_file.close()
+        if len(self.error):
+            print("\n\nWhile creating the blocklist the following problems occured:")
+            print("\n".join(self.error))
 
 def main():
     """