该错误通常是由于Lambda函数没有适当的KMS密钥访问权限所引起的。您可以通过以下步骤来解决此问题：

1. 确认Lambda函数角色具有kms:Decrypt权限。

2. 检查Lambda函数是否具有正确的密钥策略授权。例如，以下是一个Lambda函数可以使用的KMS密钥策略示例：

{
    "Version": "2012-10-17",
    "Id": "key-policy-1",
    "Statement": [
        {
            "Sid": "Enable IAM User Permissions",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:root"
            },
            "Action": [
                "kms:*"
            ],
            "Resource": "*"
        },
        {
            "Sid": "Allow access for Key Users",
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:user/USER-NAME",
                    "arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:role/ROLE-NAME"
                ]
            },
            "Action": [
                "kms:Encrypt",
                "kms:Decrypt",
                "kms:ReEncrypt*",
                "kms:GenerateDataKey*",
                "kms:DescribeKey"
            ],
            "Resource": "*"
        },
        {
            "Sid": "Allow attachment of persistent resources",
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:user/USER-NAME",
                    "arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:role/ROLE-NAME"
                ]
            },
            "Action": [
                "kms:CreateGrant",
                "kms:ListGrants",
                "kms:RevokeGrant"
            ],
            "Resource": "*",
            "Condition": {