There is nothing wrong with the link to your css styelsheet. The error is refering to some other code in your page which probably has an unclosed tag.
Use the online markup validation service to check your code.
From DW CC, go to Window > Results > Validation. Check your document.
A well-formed HTML document should look something like this:
<!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <title>Unique Page Title</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="Tinne.css" rel="stylesheet" type="text/css"> </head> <body> PAGE CONTENT GOES HERE </body> </html>