Why do I get these Simulink errors?

Can anyone give me an idea why I get the errors shown in this picture: http://img688.imageshack.us/img688/2416/fuzzyy.png?

Answer 1

[Ryan G]

It appears to be like an algebraic loop. Try putting a 1/z in the feedback path to see if it resolves some/most of those errors.

[aletsoup]

I had the same idea in the morning and it worked just fine. Thank you for your time.