Can't save Group Classification settings

Getting this error in the reponse:
MessageText=An internal server error occurred. The operation failed.
MessageXml=<?xml version="1.0"?>
<XmlNodeArray xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns="http://www.w3.org/2001/XMLSchema-instance">
<t:Value Name="InnerErrorMessageText">
Request_BadRequest
Property classification is invalid. <<<<< This seems to be the issue ...
request-id: f9d4abec-4fa4-4f80-80e0-26d9d7b03206
Date: Tue, 30 Aug 2016 07:24:23 GMT
ocp-aad-diagnostics-server-name: mGubvLpN4gmR6g807pUdhnRaa0vTbq3Wp+iA0SbDeV8=
</t:Value>
<t:Value Name="InnerErrorResponseCode">ErrorUnifiedGroupMailboxUpdateFailed</t:Value>
<t:Value Name="InnerErrorDescriptiveLinkKey">0</t:Value>
</XmlNodeArray>
ResponseClass=Error
ResponseCode=ErrorInternalServerError