Error while Synchronizing Products to CPQ

Summary:

We are getting error when opening OOTB Synchronize Products with CPQ ( DATAINTG-100 )
Error:

Status : 400{"title":"Bad Request","status":"400","o:errorDetails":[{"detail":"The response from the target application couldn't be parsed. Verify the integration map and try again. (ZCA-210427)","o:errorCode":"ZCA:::ZCA_DATA_INTEG_CNNOT_PARS_RESP"}]}

Content (please ensure you mask any confidential information):

We are trying to synch the products from Sales to CPQ using the OOTB integration but getting error when trying to open existing or add /copy the existing mapping.

We have set up the connection to add the CPQ user.

Also, we observed, The Target Object is not populated