Calibre fails to start

[John Smith]

Tried to start 64 bit windows version and portable version on a PC running Win 10 Pro. Both versions yielded the same error message.
calibre, version 3.1.1
ERROR: Startup error: There was an error during calibre startup. Parts of calibre may not function. Click Show details to learn more.

Traceback (most recent call last):
  File "site-packages\calibre\gui2\main.py", line 292, in initialize_db_stage2
  File "site-packages\calibre\gui2\main.py", line 232, in start_gui
  File "site-packages\calibre\gui2\ui.py", line 250, in initialize
  File "site-packages\calibre\gui2\layout.py", line 330, in init_main_window_mixin
  File "site-packages\calibre\gui2\actions\fetch_news.py", line 32, in init_scheduler
  File "site-packages\calibre\gui2\dialogs\scheduler.py", line 587, in __init__
  File "site-packages\calibre\web\feeds\recipes\model.py", line 148, in __init__
  File "site-packages\calibre\web\feeds\recipes\collection.py", line 103, in get_builtin_recipe_collection
  File "src/lxml/lxml.etree.pyx", line 3442, in lxml.etree.parse (src\lxml\lxml.etree.c:81716)
  File "src/lxml/parser.pxi", line 1811, in lxml.etree._parseDocument (src\lxml\lxml.etree.c:118635)
  File "src/lxml/parser.pxi", line 1837, in lxml.etree._parseDocumentFromURL (src\lxml\lxml.etree.c:118982)
  File "src/lxml/parser.pxi", line 1741, in lxml.etree._parseDocFromFile (src\lxml\lxml.etree.c:117894)
  File "src/lxml/parser.pxi", line 1138, in lxml.etree._BaseParser._parseDocFromFile (src\lxml\lxml.etree.c:112440)
  File "src/lxml/parser.pxi", line 595, in lxml.etree._ParserContext._handleParseResultDoc (src\lxml\lxml.etree.c:105896)
  File "src/lxml/parser.pxi", line 706, in lxml.etree._handleParseResult (src\lxml\lxml.etree.c:107604)
  File "src/lxml/parser.pxi", line 646, in lxml.etree._raiseParseError (src\lxml\lxml.etree.c:106750)
XMLSyntaxError: None (builtin_recipes.xml, line 0)

I have tried a repair with the install file with no change.

[John Smith (callant)]

Went back to version 3.0.0 portable and Calibre started OK but latest will not start.

[Kovid Goyal (kovid)]

This is caused by the third party iOS Reader plugin. You can fix it by following the steps:

    1. Tell calibre to ignore plugins by starting calibre from a command prompt
       by typing the following and pressing Enter:

       calibre.exe --ignore-plugins

    2. Go to Preferences->Plugins

    3. Click "Show only user installed plugins"

    4. Remove the "iOS reader applications" plugin

    5. Remove (if installed) the "Marvin XD" plugin

    6. Quit calibre. Now you should be able to use it as normal.

In the next calibre release, this plugin will be blacklisted so calibre
does not load it.

Note that if you are on a Mac, instead of using "calibre.exe", use
/Applications/calibre.app/Contents/MacOS/calibre

On Linux, use "calibre" instead of "calibre.exe"

 status fixreleased

[John Smith (callant)]

I followed the advice and confirmed I had already removed the Marvin plug in in Version 3.0.0 . Version 3.0.0 ran with the Marvin plug in loaded, but with a message saying it required the iOS plug in. When I update to 3.1.1 Calibre fails to start with the same error message. This applies even when I try to run using the ignore-plugins switch from the command prompt.

[John Smith (callant)]

Saw the post on mobile read and deleted the plugin files- this worked