Hi Ben,
I met the same problem.
I fixed it by updating my SAP HANA Client.
Maybe the link following can help you.
You can get the new version HANA client here (revision 60).
https://hanadeveditionsapicl.hana.ondemand.com/hanadevedition/
I agree with Racindra.
Please check your path to regi.exe first.
Make sure it is in compliance with your Studio version.
Regards,
Kevin