Simulink Error and Problem Interpreting

I'm new to Simulink. I don't understand certain errors that Simulink is generating. It says "algebraic loop". It also says that there is a block that is producing a "not a number" (NaN) error. It is computing a square root of sum of squares value (so it must produce a real number). The squared values must be positive real number. By adding them together they must therefore produce a positive real number. The square root of a positive real number is also a positive real number. It is being divided by "533". So it can't be a division by zero problem. I'm more than confused. This is a sufficiently complex model that I'm about to give up on it. Any help? Thanks in advance.

[Mathieu NOE]

An algebraic loop generally occurs when an input port with direct feedthrough is driven by the output of the same block, either directly, or by a feedback path through other blocks with direct feedthrough. (See Nonalgebraic Direct-Feedthrough Loops for an example of an exception to this general rule.)

How Simulink Works (Using Simulink)

Algebraic Loop Concepts - MATLAB & Simulink

to avoid this situation,we usually use a delay (z^-1) or memory block in the feedback path

[DJ V]

I think that it is possible that the fact that there are no initial values for the variables used in the square root of the sum of the squares equation may be the problem. How can I fix this with Simulink? Please be specific regardings the block that I'm to use and its name. How to configure it? Thank you.