"Unable to load package manifest camera" error

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Hello all,

I'm trying to subscribe a camera/image_raw topic via rosbridge (with other various topics), and I keep getting this error. The main issue is, cameras are not a custom package (other similar errors are solved by installing those packages anyways). All other topics subscribe correctly. Also, when I unsubscribe, I get many lines of errors ending up with a "Key_Error: /camera/image_raw". Any ideas on what I can do? I'm using Ubuntu Linux and ros-melodic. Appreciate it in advance.