Here's why:
* "Pero" means "but" and acts as a conjunction, connecting two clauses.
* "Me gusta" means "I like" and is used to express your preference for something.
You need something after "pero" to complete the sentence. For example:
* Me gusta el perro, pero no me gusta el gato. (I like the dog, but I don't like the cat.)
* Me gusta el color azul, pero no me gusta el rojo. (I like the blue color, but I don't like the red color.)
It seems like you might be trying to say something like "I like the... but..."
Can you please tell me what you want to say? I'd be happy to help you translate it correctly!