QlikView is a different animal to SQL and is designed for analytical BI, whereas SQL is designed for transactional systems. Doing things the QlikView way results in good scripts and good data models. Fighting against QlikView and trying to do things the SQL way results in pain.
There is an old saying about square pegs and round holes.
Re: Why doesn't multple SQL Joins script work in QlikView? Even though it works in standard SQL engine
Such behaviour has nothing to do with qlikview then qlikview didn't perform the sql-statement - qlilkview transferred only the sql-statement per odbc/oledb-driver to the database which then execute the query and returned the result to qlikview again.
In your case might maybe the driver not appropriate or the query take too long and any timeouts happens or your network isn't stable enough. But before I would check if your user has the proper access-rights to your second join-table Employees which will be probably have some restrictions. Sometimes are external queries on certain data forbidden, too.