Occasional Contributor
Posts: 5

Polycom VVX/CX phones periodically say "Lync Sign In has failed. Please update Sign In Information"




We have a few Polycom phones in our region (many more in the future) and periodically they will display a message indicating that the Lync Sign In has failed.  This happens with phones that are using a PIN login, a manual SIP login, and phones that are connected to a PC and receive their credentials from the Skype for Business client.


Most recently I happened to notice this happen while I was at my desk on a Polcyom VVX500 which is getting credentials from the connected computer (Better Together).



  • Lync 2013 Servers (On-Premise obviously)
  • FTP provisioning server


Error message on the phone display

Lync Sign In has failed

Please update Sign In information



 Afterlogging back in successfully almost immediately after the VVX500 complained that the Lync Sign in failed, I tried:

  • Restarting the phone
  • Rebooting the phone
  • Unplugging the phone and plugging it back in
  • Unplugging the phone and the attached computer (that it is getting it was credentials from)


Each time it logged in successfully and automatically without me having to re-enter credentials.


Example Devices

Here are two example phones and versions we are currently using, but this issue has persisted through a few different software version updates:


Polycom VVX500

  • UC Software version:
  • Login Type: "Better Together" (from computer)


Polycom CX5500

  • UC Software version:
  • Login Type: PIN


Thank you!

Polycom Employee & Community Manager
Posts: 13,995

Re: Polycom VVX/CX phones periodically say "Lync Sign In has failed. Please update Sign In Inf

Hello stuzzicadenti,

welcome back to the Polycom Community.

The community's Skype for Business FAQ contains this post here:

Jan 17, 2017 Question:How can I troubleshoot simple Skype for Business, LYNC or Office365 issues?

Resolution: Have a look => here <=

Please ensure you always check the community FAQ and/or utilize the community search before posting any new topics or follow up post’s.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

Please be aware:

The purpose of these forums is to allow community members collaborate and help each other.
Questions posted here do not follow Polycom’s SLA guidelines.
If you require assistance from Polycom technical support, please open a
web service request or call us .

The above is necessary in order to track issue internally within Polycom.

You are welcome to post more questions or configuration or logs for other community members to look at but if your issue requires a fix via Polycom you must go via the official support structure.

Please ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's

Please remember, if you see a post that helped you , and it answers your question, please mark it as an "Accept as Solution".

This forum reply or post is based upon my personal experience and does not reflect the opinion or view of my employer.
Polycom employee participation within this community is not mandatory and any post or FAQ article provided by myself is done either during my working hours or outside working hours, in my private time, and may be answered on weekends, bank holidays or personal holidays.
Occasional Visitor
Posts: 2

Re: Polycom VVX/CX phones periodically say "Lync Sign In has failed. Please update Sign In Inf

Hi stuzzicadenti, i'm experiencing the same issue with our VVX 500 phones with pretty much the same setup as yourself. 

Just wondering if you have had any success solving this issue?