This is because of missing public synonyms. When ever you create additional user other than schema owner you have to do an additional step of creating public synonyms. After creating public synonyms of all objects owned by schema owner user(RMS13DEV) who owns RMS,you have to grant your new user permission to access this sysnonyms. I think this step is mentioned in Installation guide.
Can you please specify which version of RMS you are dealing with. If it 13 and above you have to deal with security group linking. So please list down all the steps you performed so as to get an idea about missing step.
In addition to creating a database user, you must set up the user within the RMS application:
rtkstrt -> control -> setup -> user attributes (or add an entry to table USER_ATTRIB).
Don't forget to add a user/group link (from menubar of above form) (or add entry(ies) to SEC_USER_GROUP).
If your new user's database role is not DEVELOPER (n.b. must be default role), then you will also need to add entries for this new db role as to which menu items this role has access to (Tree Administration), order approval limits, etc.
In addition to the database role (which controls functional access), you have roles within RMS for access to location and merch hierarchy (i.e. data access). If the user/group link used is not the default group id 1, then you need to set up the location/product security for this new group on Control -> System -> Location/Product Security.
This list is not exhaustive of all the types of security associated with the DB role and the User Group, but it is a start.