[macnab69]

If I try to edit a book I get an error:
calibre, version 2.8.0
ERROR: Unhandled exception: <b>AttributeError</b>:'ParseWorker' object has no attribute 'worker'

calibre 2.8 [64bit] isfrozen: True is64bit: True
Windows-7-6.1.7601-SP1 Windows ('64bit', 'WindowsPE')
('Windows', '7', '6.1.7601')
Python 2.7.8
Windows: ('7', '6.1.7601', 'SP1', 'Multiprocessor Free')
Successfully initialized third party plugins: K4PC, K4Mac, Kindle Mobi and Topaz DeDRM && Quick Preferences && Find Duplicates && Save To Format && BigOven Recipe Reader && all recipes Recipe Reader && food network Recipe Reader && Count Pages && Modify ePub && Recipe Reader && Goodreads Sync && BBC GoodFood Recipe Reader
Traceback (most recent call last):
File "site.py", line 132, in main
File "site.py", line 109, in run_entry_point
File "site-packages\calibre\utils\ipc\worker.py", line 195, in main
File "site-packages\calibre\gui2\tweak_book\main.py", line 29, in gui_main
File "site-packages\calibre\gui2\tweak_book\main.py", line 72, in _run
File "site-packages\calibre\gui2\tweak_book\preview.py", line 132, in is_alive
AttributeError: 'ParseWorker' object has no attribute 'worker'

Error was there with V2.6 as well.