I just updated to the latest version of Calibre. I tried updating to the latest plugin and got a message "A problem occurred while installing this plugin. ...". The details were:
Spoiler:
calibre, version 1.19.0
ERROR: Install Plugin Failed: A problem occurred while installing this plugin. This plugin will now be uninstalled. Please post the error message in details below into the forum thread for this plugin and restart Calibre.
Traceback (most recent call last):
File "site-packages\calibre\gui2\dialogs\plugin_updater.py", line 711, in _install_clicked
File "site-packages\calibre\customize\ui.py", line 375, in add_plugin
File "site-packages\calibre\customize\ui.py", line 53, in load_plugin
File "site-packages\calibre\customize\zipplugin.py", line 195, in load
File "site-packages\calibre\customize\zipplugin.py", line 179, in load_module
File "calibre_plugins.kobotouch_extended.__init__", line 7, in <module>
File "site-packages\calibre\customize\zipplugin.py", line 179, in load_module
File "calibre_plugins.kobotouch_extended.device.driver" , line 22, in <module>
ImportError: cannot import name KEPubContainer