you need to get a secret potion to cure the kcklon just like in damond and pearl ecxpect psyduck
A Keckleon is blocking your way. You need a SILPHSCOPE to reveal it's identity.
he is in victory road.
Catch all the pokemon in the region. Get the national pokedex
You must see all 210 pokemon in sinnoh and get the national pokèdex
Near the Galactic Eterna Building,there would be tree blocking the way,use cut
you have to have done the event at spear pillar.and then the guy who was the blocking the way to sunyshore city will be gone.
Fill your sinnoh pokedex. I'm still working on that...
you go to the side of the table and stand in front of book and press A.
You must get the Devon Scope from Steven on Route 120, then you return and press 'A' when your reach the invisible barrier blocking your way to the gym. (Its actually a Keckleon in stealth)
If you mean the Psyducks blocking your way in Pokemon Diamond/Pearl/Platinum, they're on Route 210. ..However, you need to specify the game to get a precise answer.
You should be able to enter Mt Vulcan in Pok_mon Light Platinum after you have beaten Professor Ellie. If someone is still blocking the way, it is possible that your game has glitched.
You need to defeat the gym leader candice.I suggest using fire types.