Another object with the same value for property proxyAddresses already exists.

[JC_Taru]

i got this message when i assign a license for the user

[#2]

@JC_Taru 

Same 'Email' address (email address removed for privacy reasons) is already assigned under your tenant, may check the current assignment under admin center

[#3]

I got this same error message. I checked Exchange Online (Get-Recipient -Filter {EmailAddresses -like "*email-of-the-user*"}), I see no conflicts or duplicates. It is frustrating.