There are actually two camera problems.
The first is that sometimes the RMB to control the camera angle in Studio doesn't work. Sometimes using the LMB or movement keys helps, other times (like right now) it doesn't do anything. The hand cursor appears to shake in the direction I want to pan the camera but nothing happens. I did have an Advanced Camera plugin.
When I'm testing my game in Studio, I have NO camera control via RMB and zooming is nonfunctional. This is to say that I can turn using my mouse, but RMB doesn't change how mouseview works. Probably unrelated, but I cannot get scripts from the toolbox for run, crouch, zoom, etc. to work, either, even when I place them where instructed.
I get these errors in my game:
16:36:47.313 ▼ ActivateCameraController did not select a module. (x3) - Client - CameraModule:362
16:36:47.314 ActivateCameraController did not select a module.
16:36:47.314 ActivateCameraController did not select a module.
I've been having trouble with Studio eating up too much bandwidth when NOT in use during actual gameplay in Roblox (exe), so I removed all the Studio plugins, thinking one of them might be the culprit (deliberate or accidental), and also hoping it might fix the camera issues. No such luck.
Probably unrelated, but I found a couple of apparently simple viruses (Vaccine and Fire) using clone() and spread() to reproduce within the confines that their simple scripts dictated. I removed all instances, as well as a presumably fake Antivirus. The first two were very basic scripts designed to spread the script and didn't do any damage (although the latter would damage players).