Replacing your old FEIP with a VIP card with Fast Ethernet port adapters will let you run Distribute Cisco Express Forwarding. Error message: “%FIB-3-FIBDISABLE: Fatal error, slot [#]: No window message, LC to RP IPC is non-operational”.
FEIP replaced with VIP with Fat Ethernet
Dear Olivia Matthews,
This error indicates that Cisco Express Forwarding had been disabled because of the RSP or GRP didn't receive a "keepalive" from the VIP or LC. Check if you have sufficient memory on your cards. Then check the CPU utilization on your VIP or LC. If CPU utilization is high (above 95%), the VIP or LC might be too busy to send the keepalive to the RSP or GRP.
Then this link may help you solve your problem.
If your problem is not related to CPU usage, then the error message is probably caused by a bug in the software. First follow this link to check the cards that have been affected. You can try to restart Cisco Express Forwarding on those cards. Otherwise, try to upgrade to the latest version of your Cisco IOS software release to get rid of this problem as it's solved in this release.
Hope this may help you.
Best of luck.