This article explains the meaning of the following ifl reroute counter syslog messages:

During events such as interface flap, reboot, configuration change, route convergence, node failures etc., the below syslog messages are seen:

Jan  8 13:25:51  sw1 : %PFE-3: fpc0 IF: Could not increment reroute counters for ifl 131079(2)
Jan  8 13:25:51  sw1 : %PFE-3: fpc0 nh_unilist_update_weight:2239NH: Failed to inc re-route counters for nh (type Unilist, id 131097, proto ipv4), target nh (type Indirect, id 131078, proto ipv4)
Jan  8 13:25:51  sw1 : %PFE-3: fpc0 IF: Could not increment reroute counters for ifl 131079(2)
Jan  8 13:25:51  sw1 : %PFE-3: fpc0 nh_unilist_update_weight:2239NH: Failed to inc re-route counters for nh (type Unilist, id 131097, proto ipv4), target nh (type Indirect, id 131080, proto ipv4)

Certain reroute counters failed to increment for NH type Unilist next hops. Under normal conditions when a valid next hop is available, these counters increment without any errors. However, under conditions such as interface flap, reboot, configuration change, node failures, etc., the next hop may stay in a HOLD state temporarily.  And the next-hop may not get resolved for a brief period of time due to various reasons such as unavailability of the interface due to the interface being initialized.  As a result, the counter fails to increment and these error logs appear on the device during this period.

This is expected behavior. These syslog messages appear only momentarily during convergence, which happens when there is a topology change event with respect to the interface or a reboot event on the device.

There is no service impact on the device, so they can be safely ignored.