diff --git a/bigbluebutton_api_python/bigbluebutton.py b/bigbluebutton_api_python/bigbluebutton.py
index b300cbf..f598775 100644
--- a/bigbluebutton_api_python/bigbluebutton.py
+++ b/bigbluebutton_api_python/bigbluebutton.py
@@ -134,7 +134,11 @@ def __send_api_request(self, api_call, params={}, data=None):
         if data is None:
             response = urlopen(url).read()
         else:
-            response = urlopen(url, data=urlencode(data).encode()).read()
+            if isinstance(data, str):
+                data_str = data
+            else:
+                data_str = urlencode(data)
+            response = urlopen(url, data=data_str.encode()).read()
 
         try:
             rawXml = parse(response)["response"]
diff --git a/bigbluebutton_api_python/parameters/bbbmodule.py b/bigbluebutton_api_python/parameters/bbbmodule.py
index 20df5e2..e9e440f 100644
--- a/bigbluebutton_api_python/parameters/bbbmodule.py
+++ b/bigbluebutton_api_python/parameters/bbbmodule.py
@@ -14,7 +14,7 @@ def __init__(self):
     def add_slide(self, type, value, name = None):
         if type == self.URL:
             self.__urls.append(value)
-        elif type == self.files:
+        elif type == self.FILE:
             self.__files.append(value)
         elif type == self.base64s:
             self.__base64s.append([name, value])
@@ -42,8 +42,8 @@ def __slides_to_xml(self):
         for single_file in self.__files:
             if os.path.exists(single_file):
                 xml += "<document name=\"" + os.path.basename(single_file) + "\">"
-                with open(single_file, 'r') as f:
-                    xml += base64.encodestring(f.read())
+                with open(single_file, 'rb',) as f:
+                    xml += base64.encodebytes(f.read()).decode()
                 xml += "</document>"
-
+        xml += "</module>"
         return xml
\ No newline at end of file
diff --git a/bigbluebutton_api_python/responses/getmeetings.py b/bigbluebutton_api_python/responses/getmeetings.py
index 37967ec..6fc8346 100644
--- a/bigbluebutton_api_python/responses/getmeetings.py
+++ b/bigbluebutton_api_python/responses/getmeetings.py
@@ -1,3 +1,4 @@
+from typing import List
 from .base import BaseResponse
 from ..core.meeting import Meeting
 
@@ -11,6 +12,9 @@ def get_meetings(self):
         except KeyError:
             pass
 
-        for meetingXml in self.get_field("meetings")["meeting"]:
+        meetingsXml = self.get_field("meetings")["meeting"]
+        if not isinstance(meetingsXml, List):
+            meetingsXml = [meetingsXml]
+        for meetingXml in meetingsXml:
             meetings.append(Meeting(meetingXml))
         return meetings
\ No newline at end of file
diff --git a/bigbluebutton_api_python/util/urlbuilder.py b/bigbluebutton_api_python/util/urlbuilder.py
index 348a561..2322743 100644
--- a/bigbluebutton_api_python/util/urlbuilder.py
+++ b/bigbluebutton_api_python/util/urlbuilder.py
@@ -1,5 +1,6 @@
 
 from hashlib import sha1
+from urllib import request
 from re import match
 
 class UrlBuilder:
@@ -22,7 +23,7 @@ def buildUrl(self, api_call, params={}):
                 value = "true" if value else "false"
             else:
                 value = str(value)
-            url += key + "=" + value + "&"
+            url += key + "=" + request.quote(value.encode('utf-8')) + "&"
 
         url += "checksum=" + self.__get_checksum(api_call, params)
         return url
@@ -34,8 +35,9 @@ def __get_checksum(self, api_call, params={}):
                 value = "true" if value else "false"
             else:
                 value = str(value)
-            secret_str += key + "=" + value + "&"
+            secret_str += key + "=" + request.quote(value.encode('utf-8')) + "&"
         if secret_str.endswith("&"):
             secret_str = secret_str[:-1]
         secret_str += self.securitySalt
+        request.quote(secret_str, 'utf-8')
         return sha1(secret_str.encode('utf-8')).hexdigest()