Im a minecraft mod developer and I decided to update forge I download 1.6.4-9.11.1.953 and unzip it to my desktop. But I find I get a error just after MCP is done downloading. I run windows 8.1. 
  
  
================ Forge ModLoader Setup Start =================== 
MCP Detected already, not downloading 
Setting up MCP 
Patching commands.py 
patching file commands.py 
    Commands patch applied successfully 
Copying FML conf 
Creating Repackaged data 
    Creating re-packaged srg 
    Creating re-packaged exc 
    Creating re-packaged MCP patches 
Traceback (most recent call last): 
  File "install.py", line 76, in <module> 
    decompile=options.decompile, gen_conf=False) 
  File "install.py", line 17, in fml_main 
    disable_assets=disable_assets) 
  File "C:\Users\Matthew\Desktop\forge\fml\fml.py", line 1013, in decompile_mine 
craft 
    pre_decompile(mcp_dir, fml_dir, disable_assets=disable_assets) 
  File "C:\Users\Matthew\Desktop\forge\fml\fml.py", line 1061, in pre_decompile 
    download_minecraft(mcp_dir, fml_dir) 
  File "C:\Users\Matthew\Desktop\forge\fml\fml.py", line 1125, in download_minec 
raft 
    failed = download_libraries(mcp_dir, version_json['libraries'], mc_info['nat 
ives_dir']) or failed 
  File "C:\Users\Matthew\Desktop\forge\fml\fml.py", line 1181, in download_libra 
ries 
    headers = get_headers(url) 
  File "C:\Users\Matthew\Desktop\forge\fml\fml.py", line 173, in get_headers 
    response = urllib2.urlopen(HeadRequest(url)) 
  File "urllib2.pyc", line 126, in urlopen 
  File "urllib2.pyc", line 406, in open 
  File "urllib2.pyc", line 519, in http_response 
  File "urllib2.pyc", line 444, in error 
  File "urllib2.pyc", line 378, in _call_chain 
  File "urllib2.pyc", line 527, in http_error_default 
urllib2.HTTPError: HTTP Error 403: Forbidden 
Press any key to continue . . .