Diagnosis
'For approval' status was set for appropriation request &V1&. Since theapproval process uses workflow, you are required to enter the approversin partner management.
You did not enter an approver.

System Response
The appropriation request cannot be set to 'for approval' status.

Procedure
Enter one or more approvers.
If there is only one approver, it is not allowed to be the applicant.
Then you can set the status of the appropriation request to 'forapproval'.