can one use a shield in the offhand with a light weapon
 

The 5e SRD module for Hero Lab lets me equip a shield at the same time as a light weapon in the offhand, but I can't find anything to allow the same in the PHB or DMG.
Is this a bug, or am I missing something in the rules?

thanks in advance.

A 1-handed weapon is a 1-handed weapon; whether its a light, finesse, versatile, or otherwise. As long as you are proficient with a shield you can wield a 1-handed weapon with a shield. You can probably even wield a 1-handed weapon with a non-proficient shield if you are willing to take Disadvantage on all d20 rolls while doing so. :)

Mergon, I think you miss the point. I can equip a Long Sword in Hand #1, a Short Sword in Hand#2, and equip a shield as well. Shouldn't the shield take up the slot in hand #2 and thus make the Short Sword unequippable? Or the visa-versa? I too just assumed it was a bug and dealt with it by not trying to equip all three because I could nto find in the rules where I could equip all three.

Ah, yea that's a bug, though I use it as a feature myself. I created a shield bash weapon. With what you are describing I can wield my weapon and a shield bash while equipping a shield.

That is indeed a bug. Can you report it to tech support, please?

Thanks Hollis.
I just submitted a bug report for this.

Thanks for doing that. :)