The clump sensors exist to detect any irregularity in the needle bed (a broken needle, for example) or in the knitting area (yarn piling up, for example). For this to happen effectively, the metal piece needs to run in between the needle bed end and the feeders, so it is appropriately located to detect issues.
This space is small and due to this proximity to both the needle bed and the feeders, if the clump sensor gets moved slightly out of place, it will touch one of them. This will lead to the clump sensor being tripped constantly stopping the machine from running.
To proceed with correcting this situation, make sure your machine is turned off.
Next, locate the screw that is attaching the clump sensor to its holder (the red square below). It is at this point where the sensor can be pivoted to adjust its position.
Pivot the sensor until it is very close to the needle bed, once that is achieved, move the carriage slowly by hand to either end of the needle bed, to make sure it is not touching it or any of the feeders. If it touches somewhere, repeat the operation until the carriage moves across the entire bed without tripping the sensor.