Unable to calculate MD5 hash in file upload using AWS Sdk in java

Galera, I already researched in several forums and no solution solved my problem. When I upload file to S3 using the Amazon API. The following exception is thrown.

com.amazonaws.SdkClientException: Unable to calculate MD5 hash: teste.txt (O sistema não pode encontrar o arquivo especificado)
at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1622)

Caused by: java.io.FileNotFoundException: teste.txt (O sistema não pode encontrar o arquivo especificado)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(Unknown Source)

Here are my classes involved:

S3Config.java

@Bean
public AmazonS3 s3client() {
    BasicAWSCredentials awsCreds = new BasicAWSCredentials(awsId, awsKey);
    AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                            .withRegion(Regions.fromName(region))
                            .withCredentials(new AWSStaticCredentialsProvider(awsCreds))
                            .disableChunkedEncoding()
                            .build();


    return s3Client;
}

S3Service.java

@Override
public String uploadFile(Conteudo conteudo, MultipartFile multipartFile) {
    String keyname = "teste";
    try {
        File  file = conveteArquivo(multipartFile);
        s3.putObject(new PutObjectRequest(bucketName, keyname, file));
        logger.info("======================= Upload File - Done! ============================");
    }  catch (AmazonServiceException e) {
        logger.info("Exceção da AmazonSeviceException em requisições PUT, devido:");
        logger.info("Mensagem de erro:         " + e.getMessage());
        logger.info("Código HTTP:              " + e.getStatusCode());
        logger.info("Código de erro da AWS:    " + e.getErrorCode());
        logger.info("Tipo do erro:             " + e.getErrorType());
        logger.info("ID da requisição:         " + e.getRequestId());
    } catch (AmazonClientException e) {
        logger.info("Exceção da AmazonClientException");
        logger.info("Mensagem de erro:         " + e.getMessage());
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return linkBucket + keyname;
}

private File conveteArquivo(MultipartFile multipart) throws IllegalStateException, IOException {
    File convFile = new File( multipart.getOriginalFilename());
    multipart.transferTo(convFile);
    return convFile;
}

Controller

@PostMapping
public ResponseEntity<Conteudo> publicaConteudo(@RequestPart("file") MultipartFile file, @RequestPart String conteudo ) throws JsonParseException, JsonMappingException, IOException {
    Conteudo conteudoConvertido = new ObjectMapper().readValue(conteudo, Conteudo.class);
    Conteudo conteudoArmazenado = conteudoService.uploadConteudo(conteudoConvertido, file);
    return ResponseEntity.ok(conteudoArmazenado);
}

To using version 1.11.106 of the Amazon SDK. Does anyone have any idea what the reason for this exception might be? I do not know what to do.