Populating dropdown from SQL Server with ajax in C# and ASP.NET MVC

It seem that debugger doesnt enter at all at the success function. The dropdown im trying to populate is part of a modal in /Dokument/Dokument route when i press a button i get a modal with some fields. One of the fields is a dropdown which has to get values from Tipi table. In the dropdown I see nothing not even the message

ASP NET MVC Error construction INSERT with FOREIGN KEY

I have a problem with getting identity primary key from a logged user with using sql queries without Enity Framework.
So when i put login and password of user from my database UserDataController copy UserEmail (login) to WorkSpaceController and put it in public ActionResult UploadFile(string useremail) in useremail data. So I can use it in query in WorkSpaceController to get an ID with this email. But the problem is I can’t use UserID that i got as a parameter for insert query. Look at the code below