Getting error while saving password using Decrypt function

Message : The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.

Private Function Encrypt(ByVal clearText As String) As String
    Dim EncryptionKey As String = "MAKV2SPBNI99212"
    Dim clearBytes As Byte() = System.Text.Encoding.Unicode.GetBytes(clearText)
 
    Using encryptor As System.Security.Cryptography.Aes = System.Security.Cryptography.Aes.Create()
        Dim pdb As System.Security.Cryptography.Rfc2898DeriveBytes = New System.Security.Cryptography.Rfc2898DeriveBytes(EncryptionKey, New Byte() {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64, &H76, &H65, &H64, &H65, &H76})
        encryptor.Key = pdb.GetBytes(32)
        encryptor.IV = pdb.GetBytes(16)
 
        Using ms As System.IO.MemoryStream = New System.IO.MemoryStream()
 
            Using cs As System.Security.Cryptography.CryptoStream = New System.Security.Cryptography.CryptoStream(ms, encryptor.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write)
                cs.Write(clearBytes, 0, clearBytes.Length)
                cs.Close()
            End Using
 
            clearText = Convert.ToBase64String(ms.ToArray())
        End Using
    End Using
 
    Return clearText
End Function

Private Function Decrypt(ByVal cipherText As String) As String
    Dim EncryptionKey As String = "MAKV2SPBNI99212"
    Dim cipherBytes As Byte() = Convert.FromBase64String(cipherText)
 
    Using encryptor As Aes = Aes.Create()
        Dim pdb As Rfc2898DeriveBytes = New Rfc2898DeriveBytes(EncryptionKey, New Byte() {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64, &H76, &H65, &H64, &H65, &H76})
        encryptor.Key = pdb.GetBytes(32)
        encryptor.IV = pdb.GetBytes(16)
 
        Using ms As MemoryStream = New MemoryStream()
 
            Using cs As CryptoStream = New CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write)
                cs.Write(cipherBytes, 0, cipherBytes.Length)
                cs.Close()
            End Using
 
            cipherText = Encoding.Unicode.GetString(ms.ToArray())
        End Using
    End Using
 
    Return cipherText
End Function