Chrome versions 42 and greater, remove support for NPAPI plugins, the two biggest of which are Java Applets and Silverlight. You can see more in this article, including a short-term solution for re-enabling it.
- Classic UI users on Chrome won't be able to use the Java Uploader. This means if they need to upload a file greater than 25MB they will need to use Simple UI or a different endpoint
- Backup users on Chrome will not be able to download their backups with the Download applet