canceled due to internal error – CX500 and CX600

The Lync phones (CX500 and CX600) no longer sign in to Lync 2013. Error message states “Please verify that the domain entered is correct

After factory resetting the phone I still got the same error briefly followed by “Sign-in canceled due to internal error.Please try again

I tested to see if the credentials were working with:

Test-CsPhoneBootstrap -PhoneOrExt “2705” -PIN “12121”

I checked the DNS setup
Lync Phones usually require as a minimum Option 42 and Option 120 (then enable DHCP Options on the Front End with .

set-CsRegistrarConfiguration -EnableDHCPServer $true

I tested the DHCP options with the DHCPUtil.exe -emulateclient
I also ran wireshark to see the client getting the DHCP options, connecting to Lync, negotiating certificates and then just stop as if the credentials were incorrect

Even though the traces showed that the phone was getting all the required DHCP options and the phone was chatting to the Lync Front End, I still had no success signing in.

I am not hugely excited about the Phone Logs so before I resorted to digging into them I simply ran through the Lync Deployment Wizard (Step 2)…

That did the trick “sigh”

Other potential causes


About Paul B

My name is Paul Bloem and I am employed at Lexel Systems in New Zealand as a Principal Consultant for Unified Communications. I have been working on enterprise voice solutions for over 20 years. My first 10 years were spent working for a Telco in South Africa (Telcom SA). This is where all the groundwork happened as I was exposed to just about every aspect of telecommunication you could imagine. I develop an interest in PBX technologies and eventually became the go-to guy. Next, I had a 10 year run at Siemens South Africa, most of my time there was as a Technical Trainer. During this time VoIP hit the world stage, I had the privilege of introducing VoIP both as H.323 and later SIP across the Siemens HiPath 4000 solution stack. In 2008 I immigrated to New Zealand with my newly attained MCSE, I was ready to go where no PBX Techie had gone before. I was employed to explore OCS 2007 and that was pretty much the beginning of the end for me. I have been working on OCS and Lync ever since. My current role focuses exclusively on Lync and associated technologies.. That includes pre-sales, consulting, architecture and design, training and support. I even get to play in the development space from time to time - focus on play ;-) I was nominated as a Microsoft VTSP for Lync early in 2013 and also awarded Microsoft's MVP award for Lync in 2014.
This entry was posted in CX500, CX500 Internal Error, Polycom. Bookmark the permalink.

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