I want to move a family to a different neighborhood. I followed these steps: copying the family from the Export folder and pasting it into the Import folder of the neighborhood I want, but it didn't work...
Does anyone know what might be wrong?

Only the first neighborhood is supposed to have an Import folder. No matter which neighborhood you're in, you import from the Import folder in UserData. So do NOT add Import folders to UserData2, UserData3, and so on. The Import button at the top of the screen should work in any neighborhood, provided that the family is in the Import folder in UserData.

Be aware that Legacy has UserData folders in two different locations, but only ONE of those locations allows you to actually import families. The saved games are in C:\Users\YourUserName\Saved Games\Electronic Arts\The Sims 25, and that's where you should put families, NOT in the UserData/Import that's in the place where your game is installed.

Yeah! Thats works, I put the family in Import folder of UserData (even that I want to import to UserData2) and this works! Thanks!!