Some small bugfixes in the plugin handling code and a changelog entry

CHANGELOG.md

@@ -16,6 +16,8 @@
   search
 * You can now define a folder (default: `~/.octoprint/watched`) to be watched for newly added GCODE (or -- if slicing
   support is enabled -- STL) files to automatically add.
+* OctoPrint now has a [plugin system](http://docs.octoprint.org/en/devel/plugins/index.html) which allows extending its 
+  core functionality.
 
 ### Improvements
 

src/octoprint/server/__init__.py

@@ -133,11 +133,11 @@ def plugin_assets(name, filename):
 	asset_plugins = pluginManager.get_implementations(octoprint.plugin.AssetPlugin)
 
 	if not name in asset_plugins:
-		return make_response(404)
+		return make_response("Asset not found", 404)
 	asset_plugin = asset_plugins[name]
 	asset_folder = asset_plugin.get_asset_folder()
 	if asset_folder is None:
-		make_response(404)
+		return make_response("Asset not found", 404)
 
 	return send_from_directory(asset_folder, filename)
 

src/octoprint/util/__init__.py

@@ -259,7 +259,10 @@ def interface_addresses(family=None):
 		family = netifaces.AF_INET
 
 	for interface in netifaces.interfaces():
-		ifaddresses = netifaces.ifaddresses(interface)
+		try:
+			ifaddresses = netifaces.ifaddresses(interface)
+		except:
+			continue
 		if family in ifaddresses:
 			for ifaddress in ifaddresses[family]:
 				if not ifaddress["addr"].startswith("169.254."):