The missing property (db_password) is written by a control script that should log some information to these files and it'll help us determine a cause if we had their contents.
I'm assuming that in your CM - Ranger - Configuration page the value for field 'ranger.jpa.jdbc.password' is set to a valid value.
Also, do you perhaps have an @ (at) character in your password? If yes, could you try a different password without that character? You may be hitting a bug (OPSAPS-53645 is its internal ID, fixed in future releases) that did not support that password character in the original CDP 7.0 release.