Err 01 usually means the camera and lens aren’t communicating properly. First, clean the electrical contacts on both the lens and camera with a clean, dry cloth. Avoid moisture or touching the contacts with your fingers.

Because your error happens only when zoomed past a certain point, a more likely cause is an internal flex/ribbon cable issue rather than dirty contacts alone. Zooming changes the lens’s internal position, and if that cable is damaged or worn, moving past a certain focal length can stress it and trigger the error.

A temporary workaround may be to shoot wide open at the current focal length, but if the problem persists the lens will likely need professional repair, typically involving replacement of the aperture/flex cable.

So: try cleaning the contacts first; if that doesn’t solve it, service is the likely next step.