The BootRom image on the phones might need to be changed or it may have been erased. You can go to the link below to download a new BootRom image for these phones. Since you are running A2.07 AOS version you would want to download version 3.1.3C App & 4.1.4 Boot for this IP phone model. After downloading this version just unzip and upload the two files to the Polycom directory on the NV7100 using an FTP client. Then reboot the phones to have them download the BootRom image.
If you are still seeing this error after uploading these file, I would need to see the current configuration and the output from debug ip dhcp-server, debug ip ftp-server, and debug ip tftp server events capture while one of the phones is rebooting.
Once you have that debug please make a .zip file with it and the configuration file and upload it to our FTP server with the instructions below:
Open Internet Explorer web browser
Type the following URL: ftp://ftp.adtran.com
Press the Alt key, click View, and then click Open FTP Site in Windows Explorer
Double-click the "Incoming" folder
Drag and drop files from PC into the Internet Explorer window
Reply to this post with the file name so we can retrieve it
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