C# - AES encrypt-decrypt error : last block incomplete in decryption

I'm trying to encrypt and decrypt a string using AES everything. Everything work well when I'm using the same machine, but when I'm using different machine the, first to encrypt and another one to decrypt I have this error : last block incomplete in decryption.

This is my code :

public string Encrypt1(string plainText)

{
    string key = _appSettings.JwtSecret;
    byte[] iv = new byte[16];
    byte[] array;

    using (Aes aes = Aes.Create())
    {
        aes.Key = Encoding.UTF8.GetBytes(key);
        aes.IV = iv;

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

        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, encryptor, CryptoStreamMode.Write))
            {
                using (StreamWriter streamWriter = new StreamWriter((Stream)cryptoStream))
                {
                    streamWriter.Write(plainText);
                }

                array = memoryStream.ToArray();
            }
        }
    }

    return Convert.ToBase64String(array);
}

public string Decrypt1(string cipherText)
{
    string key = _appSettings.JwtSecret;
    byte[] iv = new byte[16];
    byte[] buffer = Convert.FromBase64String(cipherText);

    using (Aes aes = Aes.Create())
    {
        aes.Key = Encoding.UTF8.GetBytes(key);
        aes.IV = iv;
        ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

        using (MemoryStream memoryStream = new MemoryStream(buffer))
        {
            using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, decryptor, CryptoStreamMode.Read))
            {
                using (StreamReader streamReader = new StreamReader((Stream)cryptoStream))
                {
                    return streamReader.ReadToEnd();
                }
            }
        }
    }
}

I don't know if there is somthing wrong with my code. I tryied many differents codes but I still have the same issue.

Your example works fine for me using .Net framework 4.8.

However, you are using the initialization vector incorrectly. The IV should be random value, not just zeroes, but it is not secret, so it is fine to send this in clear text, for example prepended to the message:

[Test]
public void test()
{
    var input = string.Join(Environment.NewLine, Enumerable.Range(0, 4096).Select(i => i.ToString()) );
    var str = Encrypt1(input);
    var result = Decrypt1(str);
    Assert.AreEqual(result, input);
}
public string Encrypt1(string plainText)
{
    byte[] array;
    using (Aes aes = Aes.Create())
    {
        aes.Key = new byte[]{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11,  12, 13, 14, 15, 16};
        var iv = aes.IV;
        var encryptor = aes.CreateEncryptor(aes.Key, aes.IV);
        using (var memoryStream = new MemoryStream())
        {
            memoryStream.Write(iv, 0, iv.Length);
            using (var cryptoStream = new CryptoStream( memoryStream, encryptor, CryptoStreamMode.Write))
            {
                using (var streamWriter = new StreamWriter( cryptoStream, Encoding.UTF8))
                {
                    streamWriter.Write(plainText);
                }
                Assert.IsTrue(cryptoStream.HasFlushedFinalBlock);
                array = memoryStream.ToArray();
            }
        }
    }
    return Convert.ToBase64String(array);
}

public string Decrypt1(string cipherText)
{
    byte[] iv = new byte[16];
    byte[] buffer = Convert.FromBase64String(cipherText);

    using (Aes aes = Aes.Create())
    {
        aes.Key = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
        using (var memoryStream = new MemoryStream(buffer))
        {
            memoryStream.Read(iv, 0, iv.Length);
            aes.IV = iv;
            var decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
            using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
            {
                using (var streamReader = new StreamReader(cryptoStream, Encoding.UTF8))
                {
                    return streamReader.ReadToEnd();
                }
            }
        }
    }
}

Your error message suggest an issue with the final encryption block, possibly caused by an issue with disposing streams. The crypto stream needs to be disposed, or have an explicit call to FlushFinalBlock before the result is used. This should be done by StreamWriter when it is disposed, but I cannot find any documentation to confirm this, and it is possible that this could depend on the .net version.

I would suggest adding Assert.IsTrue(cryptoStream.HasFlushedFinalBlock); before memoryStream.ToArray(). If that fails you need to insert a call to FlushFinalBlock.