Do you know, that… ?

Version of SolidWorks 2021 can be selected as a type in the properties window Equation.

Unfortunately, it can happen, that opening files welded construction from older versions to newer than 2021, description error occurs. It is a consequence of this, that the program replaces the type z Text on Equation.

To make a mistake “The syntax for this equation is invalid” to fix, set the type as in the second column again Text.