There is no error, it just doesn't multi-select. I am using Evernote for Mac, but with a windows keyboard - so initially I thought it may be something to do with that, but I can CTRL select files on other applications, so it seems to be an Evernote thing. Not only does it not multi-select, but when I click on a tag, the correct notes display on the right, however there is no indication of which tag has been selected. ie. the tag in the list on the side menu does not stay highlighted once selected - I can't see anyone else's screen to see if this is just an error on my machine or how Evernote for mac works.