Cannot enumerate non-scalar. a!hierarchybrowsertreefield

"Scalar" data is any singular value like a single integer or text. "Non-scalar" means this is a list of some sort.

enumerate() can on work this scalar values.

Can you share the code for more information

 a!hierarchyBrowserFieldTree(
      pathValue: local!path,
      pathSaveInto: local!path,
      nextLevelValues: 
      
     a!forEach(
        /* Make a number of values in the next level equal to the number of children */
        items: if(
          isnull(fv!nodeValue.numberOfChildren),
          enumerate(0),
          enumerate(fv!nodeValue.numberOfChildren)
        ),
        expression: a!localVariables(
          /* Give the new node a random number of children between 0 and 10 */
          local!numberOfChildren: wherecontains(
            tointeger(
              index(
                local!jobFunction,
                'recordType!{1ff9ad37-4289-4671-993e-73ee3f4cffff}CRI Function.fields.{5eeb91de-e4fd-4d7c-9cc3-ddb20eac48ee}id',
                {}
              )
            )[fv!index],
            tointeger(
              index(
                local!jobFamilyGroup,
                'recordType!{0ac046d5-58a9-4d1e-8c9c-19b64a5a95c9}CRI JF Group.fields.{a021ee14-ea90-44e2-8b54-1bc298294834}jfgid',
                {}
              )
            )
          ),
          /* Make only even nodes drillable */
          local!isDrillable: true(),
          {
            a!map(
              id: fv!item,
              name: index(
                local!jobFunction,
                'recordType!{1ff9ad37-4289-4671-993e-73ee3f4cffff}CRI Function.fields.{a11ba965-2b5a-4a8b-9b31-6baad64974f0}functiontype',
                {}
              )[fv!index],
              description: "Description for node " & index(
                local!jobFunction,
                'recordType!{1ff9ad37-4289-4671-993e-73ee3f4cffff}CRI Function.fields.{a11ba965-2b5a-4a8b-9b31-6baad64974f0}functiontype',
                {}
              )[fv!index],
              details: if(
                local!isDrillable,
                if(
                  length(local!numberOfChildren) = 1,
                  "I have 1 child node",
                  "I have " & length(local!numberOfChildren) & " child nodes"
                ),
                "I am not drillable"
              ),
              type: if(
                fv!nodeValue.type = "AIRPLANE",
                "FOUNTAIN_PEN",
                "AIRPLANE"
              ),
              numberOfChildren: local!numberOfChildren,
              isDrillable: true()
            )
          }
        )
      ),
      nodeConfigs: a!hierarchyBrowserFieldTreeNode(
        id: fv!nodeValue.id,
        label: fv!nodeValue.name,
        description: fv!nodeValue.description,
        details: fv!nodeValue.details,
        image: a!documentImage(
          document: if(
            fv!nodeValue.type = "AIRPLANE",
            a!iconNewsEvent("PAPER_AIRPLANE"),
            a!iconNewsEvent("FOUNTAIN_PEN")
          )
        ),
        isDrillable: fv!nodeValue.isDrillable,
        nextLevelCount: fv!nodeValue.numberOfChildren
      )
    )

Please refer once

There could be a possibility that fv!nodeValue.numberOfChildren is taken as list. Casting it to integer should solve it. Please replace the code items of foreach()

if(
isnull(fv!nodeValue.numberOfChildren),
enumerate(0),
enumerate(cast(1,fv!nodeValue.numberOfChildren))
)

Try replacing fv!nodeValue.numberOfChildren with

tointeger({fv!nodeValue.numberOfChildren})

I suspect the issue to be in line 15. Using wherecontains() will always return a ist of items.