I cant receive channel 518

[Reo]

I cant get channel 518

[TimmyBGood]

@Reo 

Loss of any single channel is typically due to a technical (or financial) issue at the channel end which means they aren't providing a content upload into the satellite infrastructure for distribution.

Having more than one (or a bunch of channels) missing tends to indicate a dish misalignment at the subscription address.

[xenon81]

If 518 still isn't working, check 507 (NHK World). That channel is broadcast on the same frequency. If that isn't working either you will need an engineer visit to check dish alignment etc.