Make sure the silver end is fully unscrewed each time you use it before you fully screw in the black end. Otherwise the black part will not engage many threads in the crank arm, and strip the threads in the crank arm. (You can learn by my mistakes.)Hey Matt - that looks like the right tool (on my phone) to remove the cranks. Take out the centre of a crank with a Allen key and then insert and screw in the black end into the thread. then you can use the silver end with a spanner to push the crank off the spindle.might help
Most crank extractors are supplied with a fitted smaller push plate, and a larger plate which can be slipped over the smaller one for a bigger opening.I don't know about active line but the Performance CX has a hollow axle and the pin bit of my extractor was too small and went in the bore instead of pushing on the end of the axle. My answer was to get a bit of 6mm rod that goes right through the axle and engages on the crank bolt on the other side.
If you have the smaller spline crank, the correct tool was linked in the very next sentence in that link above:Thank you all for your replies. I have the same problem as WavyDavy in that the end of my tool has a small diameter that goes in the end of the threads rather than pushing on the spines. The Bosch Crank Puller mentioned by the e-bikeshop.co.uk specifically says not suitable for Active line motors!