Originally Posted by snafa
I installed this in version 0.7.57 using the newest version of plugin updater and get this error when I try to open the drop down menu. I get a different version of this error when I just click the Find Duplicates icon on the toolbar.
I had version .3.0 I think and it worked ok.
snafa - did you restart Calibre after updating the plugin? Having done so, are you still getting the error? Also, from running an old beta previously there might be some issue. Try deleting the "Find Duplicates.json" file from your plugins configuration directory.