We recently made a new website with the Everly template.
Upon using the Image Hover module, the styling wouldn't work. When we reinstalled the module, we saw that it gave the error of not being able to reach a file in the TMP folder.
Something along the lines of: JInstaller: [Root][TMP]install_***/media/js does not exist.
We fixed this issue by downloading the Ensley template and installing the Imagehover module from that install package.
Hopefully this may help you fix it, and may help others experiencing a similar problem.
With kind regards,
Daniel & Hans from Sterkmerk.eu