I'm not sure if this is a bug, a browser issue or a device issue. I've posted in bug reports to start and see where this goes. I have a Sony Xperia Z3 compact tablet running Android 5.1.1 and I have discovered that, when adding media to the Gallery, I cannot select the category or album that I want it to go in. When I tap on any of the categories, they briefly change the background colour as though they are being selected but almost immediately return to their original state. The browser being used is the latest version of Chrome for Android (version 44) though I've also tested it with version 42. The browser isn't requesting the desktop version of the site, though ticking this option doesn't make a difference. I tried replicating this on my Xperia Z1 compact phone running Android 4.4.4 using Chrome for Android 44, though this uses the 'pop out' menu system that small mobiles use rather than the one above. However when I switched the browser to desktop mode on my phone, I had the same issue as above. I also tried replicating the issue on a Nexus 7 (2012) which is also running Android 5.1.1 and using Chrome for Android 44. Although I couldn't completely replicate the issue (I also tried with desktop mode enabled) I did find that sometimes when I tapped on a category or album it didn't select, though most of the time it did. The above does seem to suggest that it could be something to do with Chrome on Sony devices, but the partial issue on a Nexus 7 could mean that it's something else. This issue was tested on XenForo Media Gallery 1.0.9 on my site and 1.1.0 here on XenForo.