I created an account to hopefully shed some light on this... i found i was running into the same issue as well. You select body, you save the flow, then it converts the body to a body/value and returns the error you are seeing. For whatever reason, after you save the value when selecting body from your array, it will default to body/value.
Before Save:
After Save:
Error Received:
Here is how i fixed it. I found that by hovering over a previous filter that is still working that the expression is simply body('<Name Of Array>'). So i went ahead and just went to the "From" field in my Select Parameter and entered in as an expression body('Filter_Array')
Hover view:
Expression Written before save:
expression written after save:
Test Run:
Post saving, it will now show the correct "body" and not "body/value" that it keeps trying to default to.
Hope this solves your issue. I cant answer as to the WHY this is happening, but this worked for me as a fix to the problem.
