I have faced exactly the same issue with composite locator at AGS 10.1 SP1 desktop. Composite locator works fine when running it from ArcGIS Desktop Python window but when running it from standalone Python script it crash. Individual locators are working without issues in both cases. For test purposes I have made composite locator with only one connected locator and that work fine. When adding second one it stops working. For locator we are using our own localized street network data.
Error stack when running script from PyScripter:
Traceback (most recent call last):
File "<string>", line 70, in execInThread
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\netref.py", line 123, in __call__
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\netref.py", line 45, in syncreq
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\protocol.py", line 343, in sync_request
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\protocol.py", line 305, in serve
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\protocol.py", line 265, in _recv
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\channel.py", line 36, in recv
File "C:\Program Files (x86)\PyScripter\Lib\rpyc-python2x.zip\rpyc\core\stream.py", line 105, in read
EOFError: [Errno 10054] An existing connection was forcibly closed by the remote host
My setup is AGS10.1 SP1, Windows 7 x64.