diff --git a/airtable/__init__.py b/airtable/__init__.py
index 56f6d1b..c5809b9 100644
--- a/airtable/__init__.py
+++ b/airtable/__init__.py
@@ -6,6 +6,7 @@
 
 import requests
 import six
+import urllib
 
 API_URL = 'https://api.airtable.com/v%s/'
 API_VERSION = '0'
@@ -94,18 +95,29 @@ def __init__(self, base_id, api_key, dict_class=OrderedDict):
     def __request(self, method, url, params=None, payload=None):
         if method in ['POST', 'PUT', 'PATCH']:
             self.headers.update({'Content-type': 'application/json'})
+        
+        encoded_url = posixpath.join(self.base_url, urllib.parse.quote(url, safe=""))
         response = requests.request(
-            method,
-            posixpath.join(self.base_url, url),
-            params=params,
-            data=payload,
-            headers=self.headers)
+            method, encoded_url, params=params, data=payload, headers=self.headers
+        )
+
         if response.status_code == requests.codes.ok:
             return response.json(object_pairs_hook=self._dict_class)
-        error_json = response.json().get('error', {})
-        raise AirtableError(
-            error_type=error_json.get('type', str(response.status_code)),
-            message=error_json.get('message', json.dumps(response.json())))
+        
+        error_json = response.json()
+        if isinstance(error_json, dict) and "error" in error_json:
+            if isinstance(error_json["error"], dict):  
+                # Expected error format
+                error_type = error_json["error"].get("type", str(response.status_code))
+                message = error_json["error"].get("message", json.dumps(error_json))
+            else:  
+                # Handle cases where error is a simple string like "NOT_FOUND"
+                error_type = str(response.status_code)
+                message = json.dumps(error_json)
+        else:
+            error_type = str(response.status_code)
+            message = "Unknown error format"
+        raise AirtableError(error_type=error_type, message=message)
 
     def get(  # pylint: disable=invalid-name
             self, table_name, record_id=None, limit=0, offset=None,