Matrix operations failing.

I am having multiple issues with matrix operations in an FEA assignment.

The first was multiplying a transformation matrix by a stiffness matrix, I got an error stating the units were incompatible.

Removing the units from everything solved this.

The second was an error with integrating inside a matrix. It said nothing was defined and I couldnt redefine any variables. It was like they were stuck with the origional variables. to solve this, I did the integration by hand instead.

Now I cannot get the local forces to transform into global.

I am unable to attach the file because this website says the contents of the attachment do not match its file type.

I will attach a screenshot instead.

Thanks in advance.