Reboot, Uninstall>Reinstall App, Contact Support

Might also want to check the Task list workflow is using, possibly create a new one and assign to test.

Hi Mario,

Instead of selecting "Edit Task Form" form the pop up menu, select "Configure" when that screen opens in the Ribbon top left you will see an Icon for "Edit Task Form" select that and the form will open.

Not sure why they don't fix or remove the Edit Task Form link in the pop out menu.

Dottie