The link error isn't quite that simple. I saw this in another recent thread as well. The problem is that the incorrect link syntax has been used. For detailed information, you can read Help:Links/Wikitext. Here are some examples:
*[[https://custom-world.fandom.com/wiki/Bee_swarm_custom_world_Wiki|this]] - incorrect syntax
*[https://custom-world.fandom.com/wiki/Bee_swarm_custom_world_Wiki this] - correct external syntax
*[[w:c:custom-world:Bee_swarm_custom_world_Wiki|this]] - correct interwiki syntax
*[[w:c:custom-world|this]] - alternative correct interwiki syntax for a wiki's homepage
Well, which pages did you read? Which wiki are you looking at as an example of what you want? You can copy what another wiki has but there is no global standard for what something like a stub template is.