VS says path name must be less than 260 characters. It is less, so why the message

check your solution straight in  D:\OneDrive\Documents\  folder and check it

dir -file -recurse | Foreach-Object {Write-Host $_.FullName.length, $_.FullName}

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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace WindowsFormsApp3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

                foreach (string path in Directory.EnumerateFiles(@"D:\OneDrive\Documents\Courses\QAASPNETMVC\Labs\04  DataStorage\01 Setup Projects\Begin", "*.*", SearchOption.AllDirectories))
                {
                    if (File.Exists(path))
                    {
                        // This path is a file
                        ProcessFile(path);
                    }
                    else if (Directory.Exists(path))
                    {
                        // This path is a directory
                        ProcessDirectory(path);
                    }
                    else
                    {
                        Console.WriteLine("{0} is not a valid file or directory.", path);
                    }
                }
            
        }
        public void ProcessDirectory(string targetDirectory)
        {
            // Process the list of files found in the directory.
            string[] fileEntries = Directory.GetFiles(targetDirectory);
            foreach (string fileName in fileEntries)
                ProcessFile(fileName);

            // Recurse into subdirectories of this directory.
            string[] subdirectoryEntries = Directory.GetDirectories(targetDirectory);
            foreach (string subdirectory in subdirectoryEntries)
                ProcessDirectory(subdirectory);
        }

        // Insert logic for processing found files here.
       public void ProcessFile(string path)
        {
            using (StreamWriter sw = new StreamWriter(@"D:\OneDrive\Documents\Courses\QAASPNETMVC\Labs\04  DataStorage\01 Setup Projects\Begin\Results.csv",true))
            {
                sw.WriteLine(path.Length + "," + path);
            }
        }
    }
}

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