(Updated May 16, 2014)
After installing Canopy 1.3, a few users (especially in non-English locations) may be unable to start Canopy, and instead will see an error message like this:
WSGI Proxy "Server" Error. ... 'ascii' codec can't decode byte
Our apologies for the trouble. We've discovered that this is due to an old unfixed unicode-handling bug in Python 2.7 itself, when users have non-ASCII (i.e. non-English) characters in some Windows registry entries. The bug is fixed in Canopy 1.5 (due in June; it had been fixed for 1.4 but the fix was dropped, sorry!)
Meanwhile, you should be able to fix it manually by simply downloading and copying one file (these instructions are for Windows 7 or 8; the fix is similar for Windows XP):
1) Download the file attached to the bottom of this article (mimetypes.py) to your desktop.
2) Set Windows Explorer to show hidden files (on Windows 7: Computer / Organize / Folder & Search Options / View / Advanced settings / Show hidden...)
3) In Windows Explorer, locate the following directory:
Canopy 64-bit version on Windows 7 or 8 (if installed for current user):
Canopy 32-bit version on Windows 7 or 8 (if installed for current user):
Canopy 64-bit version on Windows 7 or 8 (if installed for all users, to default path):
Canopy 32-bit version on 32-bit Windows 7 or 8 (if installed for all users, default path):
Canopy 32-bit version on 64-bit Windows 7 or 8 (if installed for all users, default path):
C:\Program Files (x86)\Enthought\Canopy\App\appdata\canopy-188.8.131.525.win-x86\Lib\
4) Check this directory to make sure that it has a file already in it named "mimetypes.py". If it does not, then you are not in the correct directory.
5) Copy the mimetypes.py file from your desktop to the directory that you just found. It will overwrite the existing file of the same name.
6) Start Canopy.
(FYI, optional): If you want to double-check what you just did and you know how to use an editor, lines 250 and 272 of the old (buggy) version of this file say (after indentation):
whereas in the new (fixed) version, they say: