Hello! We use composer to manage our plugin/theme dependencies, and we’ve set up a custom, private composer repo to host any paid/non-public zip archives. On occasion, one of these zips will include the hidden _MACOSX thumbnails folder if the developer’s build process forgets to exclude those in the archive creation step. When composer unzips the folder, it doesn’t correctly extract the files in the folder at the root level, and this will cause the plugin (or theme, in this case) to be deactivated. It’s simple enough to delete it from the zip before I add it to the protected repo, but sometimes I forget, and then I have to retrace my steps to figure out what broke.
As far as I can remember, I think this only happened with the 1.7.1 release.