[davidfor]

Originally Posted by DNSB

Sorry but for me, the install errors out either running the binaries or running from source. BTW, was the run.cmd supposed to be in the .zip file?

calibre, version 5.1.0
ERROR: Unhandled exception: <b>ImportError</b>:cannot import name 'KOBOTOUCHEXTENDED' from 'calibre_plugins.kobotouch_extended.device.driver' (<calibre Plugin Loader>)

calibre 5.1* [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.19041-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19041')
Python 3.8.5
Windows: ('10', '10.0.19041', 'SP0', 'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: DeDRM (7, 0, 0) && Annotations (1, 12, 0) && Baen (1, 2, 0) && Calibre Power Search Plugin (1, 6, 0) && Count Pages (1, 10, 0) && Diaps Editing Toolbag (0, 3, 6) && EpubCheck (0, 2, 3) && EpubMerge (2, 11, 0) && EpubSplit (2, 9, 0) && FanFicFare (3, 23, 0) && Fantastic Fiction (1, 4, 0) && Find Duplicates (1, 7, 5) && Goodreads (1, 5, 1) && Hyphenate This! (0, 1, 3) && Job Spy (1, 0, 184) && Kindle hi-res covers (0, 5, 0) && KindleUnpack - The Plugin (0, 82, 3) && Kobo Books (1, 8, 0) && Kobo Utilities (2, 11, 5) && Modify ePub (1, 6, 0) && Obok DeDRM (6, 7, 0) && Open With (1, 5, 12) && Quality Check (1, 10, 1) && Resize Cover (1, 1, 0) && ScrambleEbook (0, 4, 5) && SmartEject (2, 3, 0) && Smashwords Metadata (1, 0, 2)
Traceback (most recent call last):
  File "C:\Users\David\work\calibre\src\calibre\gui2\preferences\plugins.py", line 317, in add_plugin
  File "C:\Users\David\work\calibre\src\calibre\customize\ui.py", line 472, in add_plugin
  File "C:\Users\David\work\calibre\src\calibre\customize\ui.py", line 61, in load_plugin
  File "C:\Users\David\work\calibre\src\calibre\customize\zipplugin.py", line 200, in load
  File "C:\Users\David\work\calibre\src\polyglot\builtins.py", line 123, in reload
  File "importlib\__init__.py", line 169, in reload
  File "<frozen importlib._bootstrap>", line 602, in _exec
  File "C:\Users\David\work\calibre\src\calibre\customize\zipplugin.py", line 184, in load_module
  File "calibre_plugins.kobotouch_extended.__init__", line 9, in <module>
ImportError: cannot import name 'KOBOTOUCHEXTENDED' from 'calibre_plugins.kobotouch_extended.device.driver' (<calibre Plugin Loader>)

Weird. It works here. And I have to admit, my first thought is that you have tried installing the wrong version. Anyway, I have made a couple of other changes with what Kovid said in mind. Can you try the attached version?

Also, the released version is working here with the 5.1.1 beta. Or at least the portable version of the beta.