When writing an expression analysis with many variables, if there is a missing ")" or an extra ")" then the whole analysis will not evaluate with error "Equation not set." This error does not help the user identify where the issue is. If PSE would back-light highlight the variable row in question or include the variable name within the error these would be much easier to identify and would save a lot of headache.
In the attached screenshot is an example of "equation not set" where the issue is visible in the screenshot, but difficult to identify.