Error on clicking any Approval workflow in Manager tool


When we are clicking on any Approval Workflow in Manager tool, we are getting the below error.

Form (FormDecisionWorkFlow) from archive (QER.Forms) could not be created!
The form definition could not be applied to form (FormDecisionWorkFlow)!
The component (ChildRelation1) does not exist!

We are unable to open or create any approval workflow. Please let us know how we can resolve this.