I suppose the client has no activity, hence the message.
You can validate it by running below:
#ganesha_stats list_clients
Typical o/p will be as below:
$ ganesha_stats list_clients
Timestamp: Wed Jan 22 12:37:40 2020165232526 nsecs
Client List:
Address: ::ffff:127.0.0.1
NFSv3 stats available: 0
MNT stats available: 0
NLM4 stats available: 0
RQUOTA stats available: 0
NFSv4.0 stats available 0
NFSv4.1 stats available: 0
NFSv4.2 stats available: 0
9P stats available: 0
Address: ::ffff:192.168.122.243
NFSv3 stats available: 0
MNT stats available: 0
NLM4 stats available: 0
RQUOTA stats available: 0
NFSv4.0 stats available 1
NFSv4.1 stats available: 0
NFSv4.2 stats available: 0
9P stats available: 0
If it is 0 for all fields for that client (like ::ffff:127.0.0.1 in above), then client_all_ops will fail.