What Security level do you have set? In the Modeler, expand the Project branch and choose the Security leaf. If you set the Security to Off you will not need to log in at all. If you set the Security to Prototype/Demo or Production, you will need to log in.
In these latter cases, you need an initial login for the MxAdmin account. When you select one of these settings extra tab pages become visible. Go to the Administrator tab and set the password to use there.
You should then be able to log in when running the application in the Modeler.
If you install the Mendix Service Console you can set the Administrator password in the Console tab under the Advanced menu.
As far as copying data, if your development system used an SQL database then you may be able to copy that across. If you used the Built-in HSQL flat file database, you probably cannot copy that data to your new database
thanks for the reply. Yes, I was looking for the option of setting (creating) the administrator. Thanks to your reply I could find it.
The DB back end is MS SQL. But what do you mean by copying the data. Do you mean using the tools in MS SQL to copy the data?