Thanks for the quick reply, Bezo. No it doesn't have any extra cameras or anything, happened mid editing an object. It fixed itself after a full system restart (Just restarting Cinema 4D wouldn't do anything). Not sure how or why it fixed it, but I assume it must've been a C4D bug and not a setting toggle that I first thought it was. I'll mark this as 'solved' now.
Hi, My viewport doesn't let me rotate, move or even zoom in any view whatsoever. Not even using the default view tools in the top right. I was just modelling and all of a sudden, I must have mashed some key combination that completely locked everything. I can't even move the objects I can see, and starting a new project doesn't help. Does anyone know what's causing this? To clarify, I am using R19.