Client-SSL Profile Error: "SSL forward proxy RSA CA key is missing"??

I reproduced the error you observed on 14.1 using the data you posted. Which BIG-IP version are you using?

# curl -sku <user>:<pass> https://<mgmtIp>/mgmt/tm/ltm/profile/client-ssl -X POST \

-H "Content-type: application/json" -d@sat1

{"code":400,"message":"01071610:3: Profile /Common/cssl_my_default's SSL forward proxy RSA CA key is missing.","errorStack":[],"apiError":3}

(the file sat1 contains the data above).

If 14.1, remove tmOptions, proxyCaCert, proxyCaKey, proxySsl and proxySslPassthrough from your post data, and try again.