[Refplace]

Render computers and long range sensors useless.
ECM could become so effective that you have to use visual range.
Lower ACC on weapons so you have to shoot closer or make some of the UT weapons that are more powerful simply have a shorter range. People still desire the weapons for their power and versatility even if the range is shorter then old fashioned weapons.
Invent flicker or distortion fields that blur a target requiring you to get close enough to offset that.

Armor could absorb energy attacks more efficently then kinetic attacks which means youi need to engage in melee when your blaster does not work.