Symptoms
Getting error while creating arp permit-nonconnected as flex config in FTD running 6.2.3.x and can be able to create in earlier versions.
Work Around to fix this issue
Create a flex config text object and add variable as RP
Then create a flex config object " type A then insert the text object which we created earlier and type PERMIT-NONCONNECTED
then add this to flex config policy and assign to the device.
Tested this in 6.2.3.5 and its working.
Hope this will be useful for someone need to add this command when they needed to connect a non-connected subnet.
TAC submitted this issue as a defect with high-sev defect #CSCvn14276. so they can fix this in newer versions
-Abheesh