Did you’ve tried pair with the mouse again? Is it detected in windows device manager or another computer?

If not, then contact Razer Support and RMA it.

My dongle stopped working as well yesterday. I already contacted Razer support and they will sent me a dongle replacement. It’s weird that this happened same day as you. 

The same thing happened to mine around the same time.  Razer sent me a new mouse and dongle and then two months later the same thing happened to that set.  I assumed it was the dongle and contacted them again letting them know the situation.  They sent me a new dongle right away however I initially couldn’t get the new dongle to pair with the mouse automatically.  After doing a little research, I found that I had to download the specific Razer Mouse pairing utility you can download off their website.  https://mysupport.razer.com/app/answers/detail/a_id/6076 

my razer viper v2 pro’s dongle does not work from the beginning. can anyone help me with this?

Same issue here. Contacted razer support and they said I'd have to send my whole mouse to be exchanged, they also said I'd be contacted by the warranty team but still no news from them. Does anyone know in how long I should expect a follow up?

Reporting here to say I have the same issue. My Viper V2 Pro dongle isn’t working, so I’m going to send it in.

I did that and they sent me a new one that works.

Note that you will have to download razer's pairing software to pair your new dongle to the mouse once you get it

Same with me

Yes i had the same issue my dongle doesnt work

i am having the same issue, my computer does not recognize the wireless usb dongle, works fine with wire connection

Same problem.  The dongle has completely failed. No response on any computer. Tried everything I could find. The official solution is ineffective because the computer won't recognize  dongle at all. You can't even update it. really disappointing .  MY S/N nmber is PM2218H24503694    

Same. Mine dongle can’t be recognized by my pc. It’s just broken suddenly.

thanks , really worked , amazing 

is this oonly for the hyperpolling dongle ? or it works with the normal dongle ?

Hello gentlemen. I found an interesting and easy way to fix the dongle, I carefully disassembled it, separated the plastic from the electronic board and put the board in a foil cup. This cup I placed in a preheated oven at 230 degrees Celsius for 5 minutes. After taking it out, I let the board cool down and put everything back together. Now everything works as before.

Since I live in a remote region of Russia, I couldn't think of anything else that would help me fix it.

Thank you for your attention!

I actually did the same , like 2 weeks ago and it’s been working perfectly.

thanks for sharing tho