According to the manual, a blinking green LED means charging failure. Apparently, the camera for some reason thought it could charge itself via the USB hub which can't supply enough power for charging.

To resolve the issue, the manual recommends unplugging the cable and reattaching the battery. Actually, to me, the solution was just to open the battery door: apparently, the camera has a sensor for the battery door and if it's opened it automatically resets itself.

The camera is not broken. A blinking green LED problem can be solved by just opening the battery door.

The issue was probably some transient flaw, as subsequent trials resulted in a working connection between the camera and the computer.

If the issue persists, one way to improve the connection is to turn on the camera first and only then connect the cable. This way, the camera shouldn't even attempt USB charging (which requires camera power to be off).

Another improvement is to use a USB port supporting USB power delivery, if any (without any hubs inbetween). Then charging should also work.