OK, so I've followed the instructions and downloaded JRummy's SDFix - says that it is changed, but it still doesn't work. Then I edited the platform.xml file manually with the space, and it allowed me to copy a couple of test pictures to a folder on the SD card, but then I opened the folder where I just copied the files again, and they have vanished.
I am really lost on this one. Normally I don't have such a problem with anything tech related, but this issue is really throwing me for some loops. This is the most frustrated I've ever been with customizing any device. Any advice? I really need to be able to use my SD card!
I'm on jrkruse's BOC4 build of Lollipop 5.0 if that's any help.