What is this trigger supposed to do, tell me that and i'll help you, otherwise like Imperial said, this looks exactly like you're lifting code from a closed map.
And if you're doing that, you're dead to me unless you can show me that you have the expressed permission of the original owner. (because it's an old map so you want to remake it and they don't have time for it and maybe they lost their local file)
Personally I do not care about if people are lifting from a map or not. I just want to make others aware it is happening and hopefully guilt trip the person into at least giving credits to the original map.
UnitGetType is in GUI. It is a function that returns a Unit subtype of Game Link type. This compiles to string but provides extra type safety in GUI limiting how you can use it. This is also know as Unit Type.
Unit Type = (Unit type of u) <Game Link - Unit>
Due to its automatic conversion to Unit Type instead of staying as a Game Link it is not available for selection in the Game Link conversion function. As such you might want to resort to some custom script to provide it as a function argument.