Relevance substitution error

(imported topic written by mgelmer23)

Any ideas why this fails with a “relevance subsitution error” in an action? It works just fine in the relevance debugger. This is the only line in the action (to simplify debugging).

parameter “SubnetFile”="{folder (pathname of parent folder of regapp “besclient.exe”) as string & “\Subnet.Txt”}"

The debugger returns this, which is what I expect it to return.

STATUS: Running action…

Command succeeded parameter “SubnetFile”=“C:\Program Files (x86)\BigFix Enterprise\BES Client\Subnet.Txt”