Task is not Opening

Are you sure that the identifier holds the task id?

a!queryProcessAnalytics(
        report: cons!RF_PROCESS_REPORT,
        contextProcessModels: cons!RF_PROCESS_MODEL,
        query: a!query(
          pagingInfo: fv!pagingInfo
        )
      )

In the grid field when I am using above code It is working as expected. Below one throwing the error

a!queryProcessAnalytics(
  report: cons!RF_PROCESS_REPORT,
  contextProcessModels: cons!RF_PROCESS_MODEL,
  query: a!query(
    pagingInfo: a!pagingInfo(startIndex: 1, batchSize: - 1)
  )
).data

I think that, as I already mentioned, fv!identifier does NOT hold the task ID. But that is something you can easily check. In my reports, I typically add one field to hold the task id and use that to create the link.

I think that, as I already mentioned, fv!identifier does NOT hold the task ID. But that is something you can easily check. In my reports, I typically add one field to hold the task id and use that to create the link.

where we find the task ID. Could you please elaborate

What do you mean? There is a tutorial in the documentation: https://docs.appian.com/suite/help/24.1/recipe-display-a-users-tasks-in-a-grid-with-task-links.html