> URI.parse "http://london_airport_transfers.hotels-london.co.uk/transfer.php"
> URI::InvalidURIError: the scheme http does not accept registry part:

It's an invalid URI - the "_" character is not permitted, only hyphens, numbers and letters. See RFC 1035

http://www.freesoft.org/CIE/RFC/1035/6.htm

> The address is valid, check yourself.

It might be able to be created within the domain admin tool that you are using to create the subdomain, and it might work with some client software, but it will cause lots of problems for others. You should change alter the name to use hyphens or Ruby will only be the first of many problems ;)

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