What kind of phone do you have? What exactly are you trying to play from your phone to the Arc?

By ‘pair’, do you mean you are trying to send a Bluetooth signal to the Arc? It doesn’t have a Bluetooth receiver in it….

I keep getting this message , I was able to pair the ERA 100  but I don't hear anything when I watch movies . I had the old system everything worked great , came across the new arc sound bar so I decided "to upgrade" my old sub doesn't pair like they said it would,  the sound bar has a continuous blinking green light and doesn't sound as "epic" as described followed by the speakers behind me not working .  Bummer 

A blinking green light means the Arc is ready to be set up. Have you gone through the setup process in the Sonos app yet?

If the setup process for the Arc is complete, go under the Arc settings in the Sonos app to add the Sub and to add the Era 100s as surrounds.

What model TV do you have?

I have a 85" Sony Bravia 3 years old with HDMI Arc/EArc my phone is a Samsung S22 . My app easily paired ERA 100's but can't find the sub and won't pair the soundbar. I've updated TV and my phone. Made sure the E Arc was "turned on" on the TV.  I've done the unplug the system hold the 8 while plugging in to reset . I've deleted the app and reinstalled.  In my settings on the App I don't see anywhere how to turn on the HDMI. Basically I want to be able to use the Arc soundbar , sub and the 100's for surround when I watch Dolby movies. I dont care about the music functions just movies and TV but I can't pair the sub or the 100's to the soundbar since it just blinks green and won't pair to my phone to complete the setup .

There is nothing to “pair” the Arc with. You need to set up the Arc first, and bond the Sub and 100’s to it afterwards. Choose a new room “name” for the Arc and try again. Once the Arc is set up you should be able to add the sub. You’ll probably need to separate the 100’s if you’ve set them as a stereo pair before you can bond them as surrounds to the Arc. 

@ nik9669a You're a genius!!! THANK YOU ! it worked!!!! Now I can agree with all the positive reviews . This system sounds insane!!!! Thank you for taking the time to respond and assist me in troubleshooting this. I was at my wits end and simply following you're instructions made this all worth it. It sounds like I'm at IMAX ! 

I got help on these forums when I had some problems, years ago. Advice I was given got my system running reliably and it’s been stable since then. I repay those that helped me by trying to help others. 
 

 I’m glad you’re sorted. But the other contributors here helped me to spot the “missing link”. It’s often a joint effort to identify a problem and resolve it. 
 

Now: enjoy! (Though it sounds like you already are )

Very true , thank you to all !  #payingitforward!