timber-multiawards 500 server error on procedure creation

Summary: if return this to item:

    "unitValue": {
                "amount": 500,
                "currency": "UAH"
            },

validation will work, but without it crashes with 500 error

STR:

1. Go to /api/procedures endpoint
2. Create procedure with next body:

{
    "sellingMethod": "timber-multiAwards",
    "auctionPeriod": {
        "startDate": "2021-01-26T16:58:17.620007+00:00"
    },
    "title": {
        "uk_UA": "Аукціон з продажу необробленої деревини",
        "en_US": "Timber english"
    },
    "description": {
        "uk_UA": "Аукціон з продажу необробленої деревини",
        "en_US": "Timber english"
    },
    "accessDetails": {
        "uk_UA": "Порядок та можливий час ознайомлення з лотом",
        "en_US": "Auction access details"
    },
    "sellingEntity": {
        "identifier": {
            "id": "12345678",
            "scheme": "UA-EDR",
            "legalName": {
                "uk_UA": "ЕДРПОУ",
                "en_US": "EDRPOU"
            }
        },
        "address": {
            "streetAddress": {
                "uk_UA": "Хрещатик, 45a",
                "en_US": "Khreschatyk, 45a"
            },
            "locality": {
                "uk_UA": "Київ",
                "en_US": "Kyiv"
            },
            "region": {
                "uk_UA": "Київ",
                "en_US": "Kyiv"
            },
            "postalCode": "01002",
            "countryName": {
                "uk_UA": "Україна",
                "en_US": "Ukraine"
            }
        },
        "contactPoint": {
            "name": {
                "uk_UA": "Україна",
                "en_US": "Ukraine"
            },
            "telephone": "+380123456789",
            "faxNumber": "+380123456789",
            "email": "admin@example.com"
        }
    },
    "lotId": "UA-PS-19991212-00000",
     "previousAuctionId": "UA-PS-1122-33-44-000000-0",
    "x_documentRequirements": {
        "uk_UA": "Вимоги до оформлення документів",
        "en_US": "Document requirements"
    },
    "value": {
        "currency": "UAH",
        "amount": 1
    },
    "guarantee": {
        "currency": "UAH",
        "amount": 1
    },
    "tenderAttempts": 2,
    "bankAccount": [
        {
            "bankName": {
                "uk_UA": "test_bank"
            },
            "accountIdentifications": [
                {
                    "scheme": "UA-accountNumber",
                    "id": "12345"
                }
            ]
        }
    ],
    "items": [
        {
            "description": {
                "uk_UA": "Україна",
                "en_US": "Ukraine"
            },
            "classification": {
                "scheme": "CAV",
                "id": "03410000-7"
            },
            "additionalClassifications": [
                 {
                    "scheme": "timberProductionYear",
                    "id": "2020"
                },
                {
                    "scheme": "timberProductionQuarter",
                    "id": "2"
                },
                {
                    "scheme": "timberSortment",
                    "id": "sRound"
                },
                {
                    "scheme": "timberLength",
                    "id": "2,2 - 3,5"
                },
                {
                    "scheme": "timberStorage",
                    "id": "01"
                },
                {
                    "scheme": "timberDiameter",
                    "id": "D1a"
                },
                {
                    "scheme": "timberSpecies",
                    "id": "BEDA"
                },
                {
                    "scheme": "CPVS",
                    "id": "QB49-3"
                },
                {
                    "scheme": "timberClass",
                    "id": "b"
                }
            ],
            "unit": {
                "code": "MTQ"
            },
            "quantity": 900,
            "address": {
                "streetAddress": {
                    "uk_UA": "Хрещатик, 43a",
                    "en_US": "Khreschatyk, 43a"
                },
                "locality": {
                    "uk_UA": "Київ",
                    "en_US": "Kyiv"
                },
                "region": {
                    "uk_UA": "Київ",
                    "en_US": "Kyiv"
                },
                "postalCode": "01001",
                "countryName": {
                    "uk_UA": "Україна",
                    "en_US": "Ukraine"
                }
            }
        }
    ],
    "minimalStep": {
        "currency": "UAH",
        "amount": 10
    },
    "discount": {"discount": false}
}

(X-R:) 64b6bc76-8ab3-4bc7-9615-9ef1dfb74217

Actual result: 500 server error

Expected result: plz investigate and fix