diff --git a/jupyter_conda/envmanager.py b/jupyter_conda/envmanager.py
index afa5a62d..a4b062b2 100644
--- a/jupyter_conda/envmanager.py
+++ b/jupyter_conda/envmanager.py
@@ -340,7 +340,9 @@ def get_info(env):
 
         return {"environments": envs_list}
 
-    async def update_env(self, env: str, file_content: str, file_name: str = "environment.yml") -> Dict[str, str]:
+    async def update_env(
+        self, env: str, file_content: str, file_name: str = "environment.yml"
+    ) -> Dict[str, str]:
         """Update a environment from a file.
         
         Args:
@@ -512,8 +514,9 @@ async def list_available(self) -> Dict[str, List[Dict[str, str]]]:
                 try:  # Skip if file is not accessible
                     with open(path) as f:
                         channeldata = json.load(f)
-                except OSError as err:
-                    self.log.info("[jupyter_conda] Error: {}".format(str(err)))
+                except (json.JSONDecodeError, OSError, ValueError) as err:
+                    self.log.info("[jupyter_conda] {!s} skipped".format(path))
+                    self.log.debug(str(err))
                 else:
                     pkg_info.update(channeldata["packages"])
             else:
@@ -527,13 +530,20 @@ async def list_available(self) -> Dict[str, List[Dict[str, str]]]:
                     )
                 except Exception as e:
                     self.log.info(
-                        "[jupyter_conda] Error getting {}/channeldata.json: {}".format(
-                            channel, str(e)
-                        )
+                        "[jupyter_conda] {}/channeldata.json skipped.".format(channel)
                     )
+                    self.log.debug(str(e))
                 else:
                     channeldata = response.body.decode("utf-8")
-                    pkg_info.update(json.loads(channeldata)["packages"])
+                    try:
+                        pkg_info.update(json.loads(channeldata)["packages"])
+                    except (json.JSONDecodeError, ValueError) as error:
+                        self.log.info(
+                            "[jupyter_conda] {}/channeldata.json skipped.".format(
+                                channel
+                            )
+                        )
+                        self.log.debug(str(error))
 
         # Example structure channeldata['packages'] for channeldata_version == 1
         # "tmpc0d7d950": {
diff --git a/jupyter_conda/handlers.py b/jupyter_conda/handlers.py
index 75fb3599..47e52614 100644
--- a/jupyter_conda/handlers.py
+++ b/jupyter_conda/handlers.py
@@ -177,7 +177,7 @@ async def get(self):
         self.finish(tornado.escape.json_encode(list_envs))
 
     @tornado.web.authenticated
-    async def post(self):
+    def post(self):
         """`POST /environments` creates an environment.
 
         Method of creation depends on the request data (first find is used):
@@ -220,7 +220,7 @@ class EnvironmentHandler(EnvBaseHandler):
     """Environment handler."""
 
     @tornado.web.authenticated
-    async def delete(self, env: str):
+    def delete(self, env: str):
         """`DELETE /environments/<env>` deletes an environment."""
         idx = self._stack.put(self.env_manager.delete_env, env)
 
@@ -263,7 +263,6 @@ async def get(self, env: str):
                 self.finish(tornado.escape.json_encode(packages))
 
     @tornado.web.authenticated
-    @tornado.gen.coroutine
     def patch(self, env: str):
         """`PATCH /environments/<env>` update an environment.
 
@@ -286,7 +285,7 @@ class PackagesEnvironmentHandler(EnvBaseHandler):
     """Handle actions on environment packages."""
 
     @tornado.web.authenticated
-    async def delete(self, env: str):
+    def delete(self, env: str):
         """`DELETE /environments/<env>/packages` delete some packages.
         
         Request json body:
@@ -300,7 +299,7 @@ async def delete(self, env: str):
         self.redirect_to_task(idx)
 
     @tornado.web.authenticated
-    async def patch(self, env: str):
+    def patch(self, env: str):
         """`PATCH /environments/<env>/packages` update some packages.
         
         If no packages are provided, update all possible packages.
@@ -316,7 +315,7 @@ async def patch(self, env: str):
         self.redirect_to_task(idx)
 
     @tornado.web.authenticated
-    async def post(self, env: str):
+    def post(self, env: str):
         """`POST /environments/<env>/packages` install some packages.
         
         Packages can be installed in development mode. In that case,
@@ -366,11 +365,8 @@ async def get(self):
                 with open(cache_file) as cache:
                     cache_data = cache.read()
             except OSError as e:
-                logger.info(
-                    "[jupyter_conda] No available packages list in cache {!s}.".format(
-                        e
-                    )
-                )
+                logger.info("[jupyter_conda] No available packages list in cache.")
+                logger.debug(str(e))
 
             async def update_available(
                 env_manager: EnvManager, cache_file: str, return_packages: bool = True
@@ -380,11 +376,8 @@ async def update_available(
                     with open(cache_file, "w+") as cache:
                         json.dump(answer, cache)
                 except (ValueError, OSError) as e:
-                    logger.info(
-                        "[jupyter_conda] Fail to cache available packages {!s}.".format(
-                            e
-                        )
-                    )
+                    logger.info("[jupyter_conda] Fail to cache available packages.")
+                    logger.debug(str(e))
                 else:
                     # Change rights to ensure every body can update the cache
                     os.chmod(