3) Solution — I added “read” permissions (in addition to the “write” permission I’d done in the last step) to the /content/uploads folder. ‘Turns out that the server needs to read stuff from there in order to complete it’s job. Made sense, once I’d gotten it going
My upload folders are already set to read-write, and I get the blank-sceen issue. It’s interesting to note that I can’t reproduce it, but a client of mine seems to get it consistently, leading me to think its some sort of client-side issue.