Hi @straes
These are "new ones" to me.
There is nothing in UI3 to automatically maximize a camera. A faulty input device (touchscreen perhaps?) is a possibility, but I have another suspicion based on your second error.
My best guess at this point is that you have configured profiles in Blue Iris that are automatically changing (likely via Blue Iris's global schedule) and the different profiles have a different cameras enabled. I think the second error could occur if you were viewing a single maximized camera when the profile changed, causing the camera group you were viewing previously to become unavailable. So when you click the image, UI3 tries to return to that previous group, but it is unexpectedly gone, and that error is caused.
Am I onto something here?
You may be on to something with the touchscreen. I'll disable it for a time and see.
As far as schedules, I'm not aware of any being active.