I can't tell you how to get this error but somehow I got it. Pylons (version 0.9.6rc2) just displays 'Internal SErver Error' on the web and in the logs is the below:

Exception happened during processing of request from ('127.0.0.1', 54930) Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/httpserver.py", line 1044, in process_request_in_thread self.finish_request(request, client_address) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/SocketServer.py", line 254, in finish_request self.RequestHandlerClass(request, client_address, self) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/SocketServer.py", line 522, in __init__ self.handle() File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/httpserver.py", line 424, in handle BaseHTTPRequestHandler.handle(self) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/BaseHTTPServer.py", line 316, in handle self.handle_one_request() File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/httpserver.py", line 419, in handle_one_request self.wsgi_execute() File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/httpserver.py", line 287, in wsgi_execute self.wsgi_start_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/cascade.py", line 92, in __call__ return self.apps[-1](environ, start_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/registry.py", line 340, in __call__ app_iter = self.application(environ, start_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/recursive.py", line 80, in __call__ return self.application(environ, start_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/errordocument.py", line 185, in __call__ app_iter = self.application(environ, change_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Paste-1.4-py2.5.egg/paste/evalexception/ middleware.py", line 186, in __call__ return self.respond(environ, start_response) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Pylons-0.9.6rc2-py2.5.egg/pylons/error.py", line 290, in respond return debug_info.content() File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Pylons-0.9.6rc2-py2.5.egg/pylons/error.py", line 332, in content result = formatter_(self.exc_value) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Pylons-0.9.6rc2-py2.5.egg/pylons/error.py", line 311, in mako_html_data css=False) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Mako-0.1.8-py2.5.egg/mako/template.py", line 114, in render return runtime._render(self, self.callable_, args, data) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Mako-0.1.8-py2.5.egg/mako/runtime.py", line 287, in _render _render_context(template, callable_, context, *args, **_kwargs_for_callable(callable_, data)) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Mako-0.1.8-py2.5.egg/mako/runtime.py", line 304, in _render_context _exec_template(inherit, lclcontext, args=args, kwargs=kwargs) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/Mako-0.1.8-py2.5.egg/mako/runtime.py", line 337, in _exec_template callable_(context, *args, **kwargs) File "memory:0x28e5770", line 95, in render_body UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 56: ordinal not in range(128)