FMC Error Request Timed Out. Retry after sometime when saving cahssis

[tahscolony]

I ran into this yesterday.  I have a pair of 3120 chassis, both configured the same with 3 instances, one is an HA pair, the other 4 independent IPS FTD.  One chassis, no issues making changes and saving, the other, if I try to modify one of the instances, and save, I get the titled error.  I can make other changes to the chassis and save, I just can't change anything under instances.  I was testing downsizing the instances to free resources to make 4 instances, got the information I needed, then recreated the instance as original on the first chassis, but when attempting it on the second chassis I get the error. Unfortunately, I unregistered the instance in order to delete and recreate, so now I have a stuck instance with no way to do anything with it since its no longer associated to the FMC and I can't delete it due to the above error. TAC case opened of course, but have had ZERO replies from them.

[marce1000 · Accepted solution]

       - FYI : https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwm41195

  M,

[Sheraz.Salim]

you can always increase the TAC case priority. You must have S3 (severity level 3) if this is an blocker in prodution and having an impact with the production network you can ask TAC to raise the severity to 1. they will give you TAC enginner on the spot and you can deal with TAC in real time.

The issue you're experiencing with the "Request Timed Out" error when saving changes to instances on one of your Cisco 3120 chassis is likely caused by a stuck configuration or registration problem. This typically occurs when an instance is unregistered from the Firepower Management Center (FMC) but remains on the chassis, preventing further modifications. To resolve this, you may need to manually clean up the instance configuration

[tahscolony]

I had done a restore to the previous day before it acted up which allowed me to delete the instances and recreate them, but that led to another issue with hung Certificates, so had some DB work to do to clear it up.  Supposed to be corrected in the next release of 7.6 FMC code.   Other than a hung task, everything is back to normal now.