Cannot merge Epub files
I'm having problems trying to use the EPub Merge plug-in. I keep getting this error message:
calibre, version 0.8.46
ERROR: Unhandled exception: <b>AttributeError</b>:'NoneType' object has no attribute 'data'
Traceback (most recent call last):
File "calibre_plugins.epubmerge.dialogs", line 82, in do_loop
File "calibre_plugins.epubmerge.dialogs", line 91, in do_when_finished
File "calibre_plugins.epubmerge.epubmerge_plugin", line 365, in _start_merge
File "calibre_plugins.epubmerge.epubmerge", line 208, in doMerge
AttributeError: 'NoneType' object has no attribute 'data'
This seems to be similar to the error message posted above. I tried editing the title and author metadata, but no luck. I'm not sure what I'm doing wrong?