Undeclared Identifier Error in Niagara Simulation Stage

Why do I get an ‘undeclared identifier’ error?

It makes no sense. ‘InCollided’ is right there. Why does it think it’s undeclared?

I’ve tried the strange get variable, set variable, get variable thing (for which I’ve never found a proper explanation other than the somewhat cryptic and misspelt comment) it does in the PBD example in Content Examples, but that doesn’t help.

It turns out this was just a very misleading error. Further down in the code I check this bool in an if statement and when I changed

!InCollided

to

InCollided == false

the error went away.