If you see below error after uploading the 12c RPD make sure you have right parameter passed at the command line .
uploadRpd Failed: Failure in trying to acquire lock. Check bi-lcm-logs or diagnostics. Error Desc Code: DESC_CODE_SERVER_EXCEPTION
This typically happens if the instances are wrong which mean -SI parameter in uploadrpd utility . Please make sure you double check and correct this .
In my case ssi is the default -SI argument value at the command line and you should be able to use cd /u00/app/Oracle_Home/user_projects/domains/bi/bidata/service_instances/ssi/metadata/datamodel/customizations to land to right path where ssi is my -SI argument.
So double check and this might be your issue and once you right service instances you should be good unless some other issues.
Also non comprehensive bi-lcm-logs tells to lookup under managed server log path and see the error description in details under file bi-lcm-rest.log.x at : /u00/app/Oracle_Home/user_projects/domains/bi/servers/bi_server1/logs