I am using version 0.9.6.2 of the Migaku Browser extension in Brave browser version 1.41.100 on macOS 11.4. My migaku language as well as the language of the .epub file I was trying to load is Spanish.
Yesterday I was trying to load an epub into the migaku reader, and although the reader initially started to load the book, it got stuck unpacking the epub file. After waiting several minutes, nothing changed.
I can share the .epub file with the developers, but I probably shouldn't post it here because it isn't public domain. Another thing to note is that although the version of the book that I am trying to load does include illustrations, there are actually not that many images in the .epub file. The size of the file is also only 4.4 MB.