I have a workflow with Flexi tasks in it. it functioned properly in our quality farm, but in our production farm, the flexi tasks show errors (the following fields must be configured - The form has control(s) that have incomplete property settings.

I am also suffering from the same problem. The form works in the editor preview but gives an indication in the Workflow task when saved.

We are encountering the same problem as well. An update available on this?

Update: opening up all input fields on by one and saving them again solved the issue for us.

This worked for me, too, although I am using a Request Approval action instead of a Flexi Task. Thanks for the tip, Glenda!

Nintex Workflows v3.1.8.0

Nintex Forms v2.9.1.0

I had same problem with Approve/Reject action's Task form.

I have opened each and every control and saved (including Approve/Reject, Comments controls). Still it did not work. When saving the form, I noticed there is a "Warning - saying that the form contains layouts designed for use with Nintex Mobile App. Some functionality enabled in your form may not be supported in the Mobile App.......". Since I am not using the Nintex Mobile Phone and Nintex Mobile Tablet, I have deleted those two layouts, and then saved the form. Then the error disappear.

Strange thing is, I see the same error in my Acceptance error where the form was originally designed, but there was no issue. But when the workflow is imported to PROD server, I see the error and had to fix it above mentioned way.

What version are you currently on?  

I have experienced this issue before when migrating workflows between different SharePoint farms. For me one the issue was with LookUp fields.  Check your task form and see if you have lookup fields or people picker fields (as they are look up fields as well).  Resolution would be to reconfigure them .

Make sure to check your mobile layouts, tablet layouts etc as well if enabled as they will suffer the same problem.

If you haven't customized the task form in any way, clicking "Reset" in the form designer will regenerate all of the field controls in a default form. That's the fastest way of doing it, but for customized forms the slow way of opening and saving each problem field may be necessary.

In case anyone else comes across this and misunderstands. Not opening all the fields of the task itself; but opening up every control(and saving) after clicking edit task form. In my personal experience, I did not have to open up label controls.