diff --git a/vcsserver/hooks.py b/vcsserver/hooks.py
--- a/vcsserver/hooks.py
+++ b/vcsserver/hooks.py
@@ -175,7 +175,7 @@ def _call_hook(hook_name, extras, writer
 
 
 def _extras_from_ui(ui):
-    hook_data = ui.config('rhodecode', 'RC_SCM_DATA')
+    hook_data = ui.config(b'rhodecode', b'RC_SCM_DATA')
     if not hook_data:
         # maybe it's inside environ ?
         env_hook_data = os.environ.get('RC_SCM_DATA')
diff --git a/vcsserver/scm_app.py b/vcsserver/scm_app.py
--- a/vcsserver/scm_app.py
+++ b/vcsserver/scm_app.py
@@ -94,13 +94,14 @@ class HgWeb(mercurial.hgweb.hgweb_mod.hg
 
     def _runwsgi(self, req, res, repo):
 
-        cmd = req.qsparams.get('cmd', '')
+        cmd = req.qsparams.get(b'cmd', '')
         if not mercurial.wireprotoserver.iscmd(cmd):
             # NOTE(marcink): for unsupported commands, we return bad request
             # internally from HG
+            log.warning('cmd: `%s` is not supported by the mercurial wireprotocol v1', cmd)
             from mercurial.hgweb.common import statusmessage
             res.status = statusmessage(mercurial.hgweb.common.HTTP_BAD_REQUEST)
-            res.setbodybytes('')
+            res.setbodybytes(b'')
             return res.sendresponse()
 
         return super(HgWeb, self)._runwsgi(req, res, repo)