3CXClient is blocked. client will have limited functionality

[TWC-3cx]

Greetings

We just upgraded to V15.5.
We are also insisting that more staff use the 3CX soft phone.

So far we only have one 3cx Client with this error message.
3CXClient is blocked. client will have limited functionality

According to the 3cx Dashboard there are 0 Blacklisted IP's.

So far google has provided no hints.
Has anyone seen this before?

Thanks

 

[3CXusername]

Possible extension's 3CX Client access is blocked.

Go to extension -> Prhone Provisioning -> From Your phones drop down, select "3CX Client" -> Under Access is "Block use of 3CX Client" checked?