While performing Routing Engine (RE) graceful Routing Engine switchover (GRES), the following syslog messages are seen on the new primary RE.

Oct  3 19:27:00.770 2020  MXVC-r019-r026 kernel: %KERN-3: jsr_sys_handle_lookup: Error: stale handle 0x100000100000000 does not match handle 0x100000500000000: Bad file descriptor
Oct  3 19:27:00.771 2020  MXVC-r019-r026 kernel: %KERN-3: jsr_iha_pri_unrepl_msg_func: Error: Invalid primary handle in msg 0x100000100000000, error=9

These syslog messages are harmless as long as the events are temporary after the nonstop active routing (NSR) switchover. They are typically seen during the disconnect phase of a socket for RE, for example when performing a switchover. These messages are seen in the unreplicate path of JSR (Junos Socket Replication), especially when the socket on which unreplicate is called is already freed. Since the ultimate aim is to close the RE socket anyway, these messages have no functional impact and can be ignored.

To stop seeing these messages, refer to KB9382 - How to prevent syslog messages from being written to the log file [juniper.net] .