My friend stopped talking to me without a reason

I have met this woman through her ex boyfriend. We clicked and even after they split up we remained friends. She is such a friendly and kind lady, and we always chat about our lives, work, and relationships.
I have been working for myself and in one of my conversation she gave me a contact of a potential client at the place where she lives. I have spoken to the guy and have planned to go and see him. I will be traveling to her city in Jan. She was happy for me and we were talking about plans, the trip and how good will be to catch up.
But something happened like 4 days ago, as she was asking if I'd also meet her ex. I told him that I'm not planning to see him. But she is concerned that I'd eventually meet him because it is a very small town. After that she stopped replying to my messages. We chat basically everyday, so I'm very concerned. I have been trying to call her, but she isn't answering the phone. She does receive the messages (iMessage), but she seems to be ignoring them. I know by a fact that she didn't leave the town for Holidays. She didn't even reply to my New Year greetings.
I don't know what to do.

She clearly doesn't want to keep in touch. There is nothing you can do but move on. Maybe she doesn't want to be friends with her ex's friends

I'm just concerned that something might have happened to her. I'd never do this to friend. I know her ex for many years, and I'm not really in touch with him. I even told her that I will not compact him.

These are her last messages:

If he knows u r coming he likely would want to see u?!?!
I just don't want to personally interact with him after all that ugliness.
I don't want him to know anything about my life.
He'd surely try to pump u for info if he knew we were in touch.
He's VERY manipulative.

I'm very sad if she stopped speaking to me because of that. I really loved her friendship. Maybe I should just cancel this trip.

I'd recommend to not post people's private messages online. Did she give you a permission?

That's actually a translation of her message. Not the original one

Well honestly total strangers can't tell you what's going on. She clearly doesn't want to talk. I don't know why. I made suggestions and you said it's not the reasons. Her messages clearly state that her ex boyfriends communication with you IS her concern. Why though i don't know. Good luck

Thank you. I'd just move on with my plans.

I'd sent her a candid and direct email expressing your concern that she has gone silent on you, just as you have explained to us above. I don't think you can make any final assumptions about this friendship yet. Maybe she is in the Carribean on a vacation? Who's to know?

You're right. I'd wait until past the holidays. If I don't hear from her, I'd message expressing my concerns. Happy New Year to you.

And to you. Keep us updated on how things go.

I will dear. Thank you again. I really hope she's ok.

Latest news is that she's ok. She thought I wasn't good enough to be her friend. Too bad because I just started doing good with my business. I was even going to give her a gift for the contact she gave me. Her loss, I will save the money and go for a nice dinner. Life goes one.

Treat yourself to a delicious meal. You don't need a friend like that. None of us need friends like that. And yes, life will go on.

Her loss.