c# encrypting and decrypting string throws bad PKCS7 padding

Question

At this point I'm quite confused about the implementation of an encryption/decryption of game data.

Write function

private void WriteEncryptedData<T>(T Data, string path)
{
    byte[] array;

    using (Aes aes = Aes.Create())  
    {  
        aes.Key = Convert.FromBase64String(KEY);
        aes.IV = Convert.FromBase64String(IV);
        aes.Padding = PaddingMode.PKCS7;

        ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

        using MemoryStream memoryStream = new();
        using CryptoStream cryptoStream = new(memoryStream, encryptor, CryptoStreamMode.Write);
        cryptoStream.Write(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(Data)));
        cryptoStream.FlushFinalBlock();
        array = memoryStream.ToArray();
    }
    
    File.WriteAllText(path, Convert.ToBase64String(array));
}

And read function

private T ReadEncryptedData<T>(string path)
{
    var data = File.ReadAllText(path);
    byte[] array = Convert.FromBase64String(data);

    string result;

    using (Aes aes = Aes.Create())
    {
        aes.Key = Convert.FromBase64String(KEY);
        aes.IV = Convert.FromBase64String(IV);
        aes.Padding = PaddingMode.PKCS7;

        using ICryptoTransform cryptoTransform = aes.CreateDecryptor(aes.Key, aes.IV);
        using MemoryStream decryptionStream = new(array);
        using CryptoStream cryptoStream = new(
            decryptionStream,
            cryptoTransform,
            CryptoStreamMode.Read
        );
        
        cryptoStream.Flush();
        result = Encoding.UTF8.GetString(decryptionStream.ToArray());
    }

    Debug.Log($"Decrypted result (if the following is not legible, probably wrong key or iv): {result}");
    return JsonConvert.DeserializeObject<T>(result);
}

For some reason I get the following error and at this point I'm worried that I'm missing something important in the implementation. I'm using hard-coded KEY and IV. I plan to generate the IV dynamically.

Failed to load data due to: Bad PKCS7 padding. Invalid length 0. at Mono.Security.Cryptography.SymmetricTransform.ThrowBadPaddingException (System.Security.Cryptography.PaddingMode padding, System.Int32 length, System.Int32 position) [0x00056] in <381999f96ea944d79e461a81dcbea654>:0 at Mono.Security.Cryptography.SymmetricTransform.FinalDecrypt (System.Byte[] inputBuffer, System.Int32 inputOffset, System.Int32 inputCount) [0x00146] in <381999f96ea944d79e461a81dcbea654>:0 at Mono.Security.Cryptography.SymmetricTransform.TransformFinalBlock (System.Byte[] inputBuffer, System.Int32 inputOffset, System.Int32 inputCount) [0x0002e] in <381999f96ea944d79e461a81dcbea654>:0 at System.Security.Cryptography.CryptoStream.FlushFinalBlock () [0x00013] in <381999f96ea944d79e461a81dcbea654>:0 at System.Security.Cryptography.CryptoStream.Dispose (System.Boolean disposing) [0x0000b] in <381999f96ea944d79e461a81dcbea654>:0 at System.IO.Stream.Close () [0x00000] in <381999f96ea944d79e461a81dcbea654>:0 at System.IO.Stream.Dispose () [0x00000] in <381999f96ea944d79e461a81dcbea654>:0