I have been designing a rogue character and it is my understanding that a rogue character is able to use light blades. Therefore I took Spiked chain training which specifies that both ends of the chain would be considered light blades. However the character builder would not accept this. I need to know if my logic is flawed or if there are other feats I need to take to make this work.
Spiked Chain Training is different from Weapon Proficiency (Spiked Chain).
Note that, in its default state, a spiked chain is a superior weapon that belongs to the flail group.
Only through taking spiked chain training does it also become a light blade. Therefore, in order to effectively use a spiked chain as light blade as thief, you must have spiked chain training. This feat counts as a multiclass feat. If you have the wrong feat, you may equip the chain but not have it be usable by certain powers, thereby having them appear "blank."
A valid and tested build would be:
Note, however, that because of the rogue's +1 to accuracy with daggers, the spiked chain offers only a rough increase of +1.03 damage on a given attack at level 1 and far less as levels increase due to the nature of scaling bonuses. Considering the difficulty of achieving combat advantage with a reach weapon, there is no normal benefit to wielding a spiked chain as a rogue.
The chain technically counts as an exotic weapon so without the exotic weapon (spiked chain) feat it will probably keep giving you trouble.