I just went to use Openwith (Sigil) PI which has been solid thru 1.27.
I can still run Sigil. Tap 'O', Use the Windows context manager to "Open with Sigil"
Spoiler:
calibre, version 1.28.0
ERROR: Unhandled exception: <b>WindowsError</b>:[Error 2] The system cannot find the file specified
calibre 1.28 [64bit] Portable isfrozen: True is64bit: True
Windows-7-6.1.7601-SP1 Windows ('64bit', 'WindowsPE')
('Windows', '7', '6.1.7601')
Python 2.7.5
Windows: ('7', '6.1.7601', 'SP1', 'Multiprocessor Free')
Traceback (most recent call last):
File "calibre_plugins.open_with.action", line 178, in open_with
File "calibre_plugins.open_with.action", line 212, in launch_app
File "subprocess.py", line 711, in __init__
File "subprocess.py", line 948, in _execute_child
WindowsError: [Error 2] The system cannot find the file specified