after claiming the starter pack in the event tab wait for a while for it to get through to your account ingame and check your item mall ( i ) or just change channel / enter a guild town / relog for it to go through.
Make sure the game is fully installed (Try pressing Verify on the patcher and make sure it successfully verify the files).
or
Try deleting Client.ini and Client_Classic.ini.
and or
Try adding the Eden Eternal Vendetta folder in your firewall/antivirus/defender exception.
If nothing from the above works try this