About [[Wikia:Welcome-message-user/en]]

Welcome-message-user ("Hi, welcome to {{SITENAME}}! Thanks for your edit to the [[:$1]] page.
Please leave a message on [[$2|my talk page]] if I can help with anything! $3")

Now this massage create red links, see example: http://uk.udp.wikia.com/index.php?title=Обговорення_користувача:AS&oldid=1509

User:127.0.0.1 ???

That sounds like a bug in the user that welcomes. Please use Wikia channels. There is nothing wrong with the L10n.