When i was installing gsx an error popped up of something like line 1, position 46 for the dll file and encode to ANSI of which i dont understand.
Ok, that's easy, the problem doesn't obviously have anything to do with our products, and it's caused by your DLL.XML file being corrupted by another faulty installed ( or by having hand-edited ), and our installer is checking it before doing any changes, because trying to modify a corrupted XML would risk corrupting it even more.
That specific error is caused by the XML encoding in the header not matching the actual file encoding, a common mistake caused by other installers that don't realize if they save the file back and change it ( for example ), from ANSI to UTF-8, they should also update the header, otherwise the file is syntactically illegal.
I believe the installer gave you a choice if you wanted to create a brand new DLL.XML from scratch, but in the case if you have other modules that require that file, they will have to be reinstalled.
A solution is to open the XML file using a text editor that lets you change the file encoding, change to ANSI, and save it back. An example of an editor that can do this, is the free Notepad++
Of course, any time you edit an XML file manually, you must also ensure your are saving it in the correct format, according to its header so, if it's like the default ( Windows-1252 ), you must save it in ANSI.
The DLL.XML file is located here:
%APPDATA%\Microsoft\FSX\DLL.XML
or here, if you have (or had) both FSX and FSX:SE installed together at any time
%APPDATA%\Microsoft\FSX-SE\DLL.XML