New International Version
Love does not delight in evil but rejoices with the truth.
New Living Translation
It does not rejoice about injustice but rejoices whenever the truth wins out.
English Standard Version
it does not rejoice at wrongdoing, but rejoices with the truth.
International Standard Version
is never glad with sin; she's always glad to side with truth, and pleased that truth shall win.
King James Bible
Rejoiceth not in iniquity, but rejoiceth in the truth;
American Standard Version
rejoiceth not in unrighteousness, but rejoiceth with the truth;
Bible in Basic English
It takes no pleasure in wrongdoing, but has joy in what is true;
Weymouth New Testament
She finds no pleasure in injustice done to others, but joyfully sides with the truth.
The word used in the first phrase for rejoice or take pleasure in is chairei, meaning to be glad. It's also used as a greeting or farewell, wishing the other person well.
The word meaning unrighteousness, iniquity, sin, or wrongdoing is adikia, meaning simply injustice or unrighteousness.
The word in the second phrase for rejoice is sunchairei -- simply tacking "with" onto "rejoice". The preface indicating "with" is sun, indicating "together with".
The word for truth is alētheia, simply truth or verity.
So the proper response to wrongdoing or injustice is not to take pleasure or happiness in it, but rather to join ourselves with what is true. The pairing here indicates that we are not merely to be glad of truth, but to gladly join ourselves to truth.