Technically, sldworks-fs.exe is a local server application that runs out-of-process relative to the main SolidWorks window. It handles the Parasolid geometry kernel operations and feature tree evaluations. By offloading these heavy calculations to a separate process, SolidWorks can:
sldworks-fs.exe is the engine that performs step 2. It "serves" the calculated feature geometry to the main sldworks.exe display interface. Consequently, this process is most active during: sldworks-fs.exe
You might see a Windows error: "The instruction at 0x... referenced memory at 0x... The memory could not be read." This indicates that a FeatureScript operation failed catastrophically. Technically, sldworks-fs