I've tried make thumbnail by plugin, but it is horribly slow. I don't have much experience of thumbnails view mode. recently my boss assign me a task to pick out portrait PDF from thousands of PDF, thenrotate them to landscape. I had written a batch command by pdfinfo and pdftk did it, but naked eyes double check is need.... for the first time in my life, I need thumbnails view mode and yet can't make it works

*edited*
not sure what why, I delete all the configuration section started by "thumbnail" entries, and paste the old setting by TC's option dialog, the issue gone. TC read the thumbnail like Explorer... anyway, happy day.