[randy@asa3.org]

For about 5 years we have been merging about a half-dozen Epub files of the articles in our quarterly journal using Calibre w/EpubMerge plugin. Until the last issue we were using Calibre V5 but we just updated to V7 and updated the plugin. We can no longer successfully merge our files and our next issue is scheduled to be released next wee. We cannot find any legible error message or reason for failure. We are doing nothing differently from the past. What can we do now?