Example form and workflow giving null pointer exception upon submission with Umbraco Forms 7.4.1

155100bd-c7a0-4a2b-a3f0-968dab9b189b.json

{
  "id": "906a4729-814f-4ee3-97f0-2abe5a9ec3af",
  "name": "Send email when Submitted",
  "form": "94175c62-a2eb-4472-be98-23c7739d6cce",
  "active": true,
  "workflowTypeId": "e96badd7-05be-4978-b8d9-b3d733de70a5",
  "executesOn": "Submitted",
  "settings": {
    "Email": "website@example.com",
    "SenderEmail": "{Email}",
    "Subject": "Enquiry via website",
    "Message": "Enquiry via website",
    "Attachment": null
  },
  "sortOrder": 0
}

e4072a66-bb01-4bdb-8ddd-0bda8060af0b.json

{
  "name": "Test Form",
  "created": "2019-05-13T14:54:16.6914531+01:00",
  "pages": [
    {
      "fieldSets": [
        {
          "caption": "",
          "sortOrder": 0,
          "id": "00000000-0000-0000-0000-000000000000",
          "page": "00000000-0000-0000-0000-000000000000",
          "containers": [
            {
              "caption": null,
              "width": 12,
              "fields": [
                {
                  "caption": "Name",
                  "tooltip": "",
                  "placeholder": null,
                  "cssClass": null,
                  "alias": "name",
                  "id": "6e065f27-4abb-49ac-a0e6-02029edefb28",
                  "fieldTypeId": "3f92e01b-29e2-4a30-bf33-9df5580ed52c",
                  "prevalueSourceId": "00000000-0000-0000-0000-000000000000",
                  "dataSourceFieldKey": null,
                  "containsSensitiveData": false,
                  "mandatory": true,
                  "regex": "",
                  "requiredErrorMessage": "",
                  "invalidErrorMessage": "",
                  "condition": {
                    "id": "00000000-0000-0000-0000-000000000000",
                    "enabled": false,
                    "actionType": "Show",
                    "logicType": "All",
                    "rules": []
                  },
                  "settings": {
                    "DefaultValue": "[%__firstname__]",
                    "Placeholder": ""
                  },
                  "preValues": []
                },
                {
                  "caption": "Telephone",
                  "tooltip": "",
                  "placeholder": null,
                  "cssClass": null,
                  "alias": "telephone",
                  "id": "5303f9a6-8667-44e0-8601-d5e3cb6cbc17",
                  "fieldTypeId": "3f92e01b-29e2-4a30-bf33-9df5580ed52c",
                  "prevalueSourceId": "00000000-0000-0000-0000-000000000000",
                  "dataSourceFieldKey": null,
                  "containsSensitiveData": false,
                  "mandatory": false,
                  "regex": "",
                  "requiredErrorMessage": "",
                  "invalidErrorMessage": "",
                  "condition": {
                    "id": "00000000-0000-0000-0000-000000000000",
                    "enabled": false,
                    "actionType": "Show",
                    "logicType": "All",
                    "rules": []
                  },
                  "settings": {
                    "DefaultValue": "[%__telephone__]",
                    "Placeholder": ""
                  },
                  "preValues": []
                },
                {
                  "caption": "Email",
                  "tooltip": "",
                  "placeholder": null,
                  "cssClass": null,
                  "alias": "email",
                  "id": "d9b790ae-880e-4a22-be49-fec040229eb2",
                  "fieldTypeId": "3f92e01b-29e2-4a30-bf33-9df5580ed52c",
                  "prevalueSourceId": "00000000-0000-0000-0000-000000000000",
                  "dataSourceFieldKey": null,
                  "containsSensitiveData": false,
                  "mandatory": false,
                  "regex": "",
                  "requiredErrorMessage": "",
                  "invalidErrorMessage": "",
                  "condition": {
                    "id": "00000000-0000-0000-0000-000000000000",
                    "enabled": false,
                    "actionType": "Show",
                    "logicType": "All",
                    "rules": []
                  },
                  "settings": {
                    "DefaultValue": "[%__email__]",
                    "Placeholder": ""
                  },
                  "preValues": []
                },
                {
                  "caption": "Your message",
                  "tooltip": "",
                  "placeholder": null,
                  "cssClass": null,
                  "alias": "yourMessage",
                  "id": "5e6dd67e-f835-495e-a4f7-d95f5303e051",
                  "fieldTypeId": "023f09ac-1445-4bcb-b8fa-ab49f33bd046",
                  "prevalueSourceId": "00000000-0000-0000-0000-000000000000",
                  "dataSourceFieldKey": null,
                  "containsSensitiveData": false,
                  "mandatory": true,
                  "regex": "",
                  "requiredErrorMessage": "",
                  "invalidErrorMessage": "",
                  "condition": {
                    "id": "00000000-0000-0000-0000-000000000000",
                    "enabled": false,
                    "actionType": "Show",
                    "logicType": "All",
                    "rules": []
                  },
                  "settings": {
                    "DefaultValue": "",
                    "Placeholder": ""
                  },
                  "preValues": []
                }
              ]
            }
          ],
          "condition": null
        }
      ],
      "caption": "",
      "sortOrder": 0,
      "id": "00000000-0000-0000-0000-000000000000",
      "form": "00000000-0000-0000-0000-000000000000"
    }
  ],
  "id": "e4072a66-bb01-4bdb-8ddd-0bda8060af0b",
  "fieldIndicationType": "MarkMandatoryFields",
  "indicator": "*",
  "showValidationSummary": false,
  "hideFieldValidation": false,
  "requiredErrorMessage": "Please complete this field",
  "invalidErrorMessage": "Please complete this field",
  "messageOnSubmit": "Thank you for your message.",
  "goToPageOnSubmit": 0,
  "xPathOnSubmit": null,
  "manualApproval": false,
  "storeRecordsLocally": true,
  "cssClass": null,
  "disableDefaultStylesheet": false,
  "useClientDependency": false,
  "workflows": [
    "155100bd-c7a0-4a2b-a3f0-968dab9b189b"
  ],
  "datasource": null,
  "submitLabel": "Submit",
  "nextLabel": "Next",
  "prevLabel": "Previous"
}