SONOS is ending support for the cr100 and it will no longer connect to a system, and all that are still connected will stop working after a update coming out April 2018. If you have some clients still using them, it might be time to upgrade them.
[Link: en.community.sonos.com]

If you have a cr100 you can fill out a this form, [Link: sonos.com] , and they will send you a $100 voucher that you can use on there web store. It’s only 1 voucher per household, I have 2 cr100’s so I submitted one with my info and gave my brother the serial number off the other one and he submitted one for him. Sonos said the voucher won’t work with the special they are running right now for the 2 play ones for $349