Why is it that everytime i put my train ticket in the machine it always says seek assistance?

i put a railway card which is valid for a month but when i put it in the machine at barriers it always says seek assistance i heard that it could be magnets that mess it up but im not sure Also does anyone know how to fix this by myself the ticket office has been closed for 2 days so i havent been able to go and ask show more i put a railway card which is valid for a month but when i put it in the machine at barriers it always says seek assistance

i heard that it could be magnets that mess it up but im not sure
Also does anyone know how to fix this by myself the ticket office has been closed for 2 days so i havent been able to go and ask
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