Wireless AP change to new device

Hello, It seems to be an old post however replying for the benefit of everyone.
While migrating from 600C to 600E, there a few things to consider,

1. Does it have the same configuration on both the devices, capwap/fabric enabled on the interface?

2. FortiAP profiles enabled?

3. Are the FortiAP and Fortigates on compatible firmware versions? A compatibility matrix is provided below;
https://docs.fortinet.com/document/fortiap/7.4.0/fortiap-and-fortios-compatibility-matrix/495193/fortiap-and-fortios-7-x-compatibility-matrix

If all the above are valid, then APs should migrate successfully to the new device. If it fails, additional debugs need to be collected as per the troubleshooting guide provided here;

https://docs.fortinet.com/document/fortiap/7.4.0/fortiwifi-and-fortiap-configuration-guide/692236/troubleshooting