Unable to Assign device to extension

[SMF Media]

Getting an Internal Server Error(500)
An item with the same key has already been added. Key: -403673701

Running Linux

 

[YiannisH_3CX]

What PBX version are you running? You can see the exact build number on the Dashboard, under the Information column next to the licence version. For example 15.5.15502.6. Also what phone are you trying to add the PBX?

 

[SMF Media]

15.5.15502.6

It is a Grandstream DP715 Fw. Version 1.0.0.33 I obtained a template from Grandstream.

 

[YiannisH_3CX]

How about using a supported device? Do you get the same error?

 

[Saqqara]

Have you checked out
https://www.3cx.com/community/threads/grandstream-dp750.55041/

How did you add the template to the system ?

 

[SMF Media]

I am waiting for additional supported phones so I don't know at this point. I did see that post that Saqqara referenced and yes I added the template. Before adding them template the button isn't even available to assign it to an extension. The Template has a comment that notes firmware version. The phone is running the most current firmware.