add on instructions, function block questions

I am troubleshooting an outside vendor program where add on instructions are used as well as these user defined function blocks. I am trying to figure out what calls for the specific solenoid to be energized, but when I cross reference the tag I keep hitting a dead end on the logic that would call for this solenoid. Can someone explain to me the best way to troubleshoot these user defined function blocks. Attached is the block with the solenoid in question. Also the Add on's are not read only.

Thanks
RM

Bad picture quality, and you need to open the actual AOI logic to understand what is going on.

Sorry about the picture. The AOI's don't seem to be interactive, they are Greyed out.

If they are grayed out the integrator probably put some security/source protection on them. Which I would argue they should be open so you can review for understanding and troubleshooting should you need it.