This doesn't directly answer your question, since you are using AMOS, but I wanted to point out that there are two approaches to SEM. One uses an approach based on covariances and maximum likelihood, the other uses an approach based on the original data and partial least squares (PLS).
I believe AMOS (LISREL, Mplus, etc) use the first approach, which is generally called SEM. The other approach, often called PLS Path Modeling (or sometimes PLS SEM) is also available in various software, including several R packages. Different horses for different courses, but as I'm learning about the PLS approach, it seems like it has advantages in many applications.