"I have a peer where I work that has become very hostile toward me and I am not sure what I did and I no idea how to address this with them. Can you help with some suggestions?"
If by hostile you mean physical abuse, physical threats and work sabotage, you should go to your manager and Human Resources immediately and report the situation. Be prepared to provide evidence of their inappropriate behavior. No one has the right to abuse you in this way.
If by hostile you mean they are indifferent, verbally abusive in private, spreading rumors in small circles, ignoring your participation, or similar actions; here are a few suggestions for you to consider:
Before you do anything, you should determine how important it is to you to restore this relationship, and how much effort are you willing to put into the situation?
If they persist in being uncooperative, then the issue should be raised to your manager first and then to Human Resources if not corrected.
The workplace is difficult and stressful enough that you should not have to endure such actions from a peer or anyone else.
I wish you the best.
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