.NET (Core and Framework)

Unregister-Event : Event subscription with identifier 'FileCreated' does not exist.
At D:\Programming\PowerShell\.Current Projects\TAB-File Watcher\out\TABFileWatcher.ps1:84 char:5
+     Unregister-Event FileCreated
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Unregister-Event], ArgumentException
    + FullyQualifiedErrorId : INVALID_SOURCE_IDENTIFIER,Microsoft.PowerShell.Commands.UnregisterEventCommand

$RSscriptblock = {
 
    $Output_RTB = $sync.RTB
    $sourceDirectory = $sync.SD
    $filter = $sync.SF
    $destination = $sync.DES

    $fsw = New-Object IO.FileSystemWatcher $sourceDirectory, $filter -Property @{
        IncludeSubdirectories = $false 
        NotifyFilter          = [IO.NotifyFilters]'FileName, LastWrite'
    }
    
    Register-ObjectEvent $fsw Created -SourceIdentifier FileCreated -Action {
        $name = $Event.SourceEventArgs.Name
        $changeType = $Event.SourceEventArgs.ChangeType
        $timeStamp = $Event.TimeGenerated
        $Output_RTB.SelectionColor = "Green"
        $Output_RTB.AppendText("The file '$name' was $changeType at $timeStamp`r`n") 
        Copy-item -Force -Recurse $sourceDirectory -Destination $destination }
    
    Register-ObjectEvent $fsw Changed -SourceIdentifier FileChanged -Action {
        $name = $Event.SourceEventArgs.Name
        $changeType = $Event.SourceEventArgs.ChangeType
        $timeStamp = $Event.TimeGenerated
        $Output_RTB.SelectionColor = "Green"
        $Output_RTB.AppendText("The file '$name' was $changeType at $timeStamp`r`n") 
        Copy-item -Force -Recurse $sourceDirectory -Destination $destination }

        $Output_RTB.SelectionColor = "Green"
        $Output_RTB.AppendText("Monitoring has Started`r`n")
        $Output_RTB.Select($Output_RTB.Text.Length, 0)
        $Output_RTB.ScrollToCaret() 
}

function Start-RSJob {
    $sync = [Hashtable]::Synchronized(@{RTB = $Output_RTB; SD = $Script:sourceDirectory; SF = $Script:filter; DES = $Script:destination})
    $rsjob = [PowerShell]::Create().AddScript($RSscriptblock)
    $runspace = [RunspaceFactory]::CreateRunspace()
    $runspace.ApartmentState = "STA"
    $runspace.ThreadOptions = "ReuseThread"
    $runspace.Open()
    $runspace.SessionStateProxy.SetVariable("sync", $sync)
    $rsjob.Runspace = $runspace
    $rsjob.BeginInvoke()
}

function StopMonitoring {
    Unregister-Event FileCreated
    Unregister-Event FileChanged
    $Output_RTB.SelectionColor = "Red"
    $Output_RTB.AppendText("Monitoring has Stopped`r`n")
    $Output_RTB.Select($Output_RTB.Text.Length, 0)
    $Output_RTB.ScrollToCaret()
}

    #
    #Start_Button
    #
    $Start_Button.BackColor = [System.Drawing.SystemColors]::Control
    $Start_Button.FlatAppearance.BorderColor = [System.Drawing.Color]::Blue
    $Start_Button.FlatAppearance.MouseOverBackColor = [System.Drawing.SystemColors]::GradientActiveCaption
    $Start_Button.FlatStyle = [System.Windows.Forms.FlatStyle]::Flat
    $Start_Button.Location = (New-Object -TypeName System.Drawing.Point -ArgumentList @([System.Int32]12, [System.Int32]54))
    $Start_Button.Name = [System.String]'Start_Button'
    $Start_Button.Size = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]130, [System.Int32]23))
    $Start_Button.TabIndex = [System.Int32]1
    $Start_Button.Text = [System.String]'Start Monitoring'
    $Start_Button.UseCompatibleTextRendering = $true
    $Start_Button.UseVisualStyleBackColor = $false
    $Start_Button.add_Click( {Start-RSJob})
    #
    #Stop_Button
    #
    $Stop_Button.BackColor = [System.Drawing.SystemColors]::Control
    $Stop_Button.FlatAppearance.BorderColor = [System.Drawing.Color]::Blue
    $Stop_Button.FlatAppearance.MouseOverBackColor = [System.Drawing.SystemColors]::GradientActiveCaption
    $Stop_Button.FlatStyle = [System.Windows.Forms.FlatStyle]::Flat
    $Stop_Button.Location = (New-Object -TypeName System.Drawing.Point -ArgumentList @([System.Int32]12, [System.Int32]94))
    $Stop_Button.Name = [System.String]'Stop_Button'
    $Stop_Button.Size = (New-Object -TypeName System.Drawing.Size -ArgumentList @([System.Int32]130, [System.Int32]23))
    $Stop_Button.TabIndex = [System.Int32]2
    $Stop_Button.Text = [System.String]'Stop Monitoring'
    $Stop_Button.UseCompatibleTextRendering = $true
    $Stop_Button.UseVisualStyleBackColor = $false
    $Stop_Button.add_MouseClick( { StopMonitoring })

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections.Specialized;


namespace Migration_Wizard {
    public partial class Form1 : Form {
        bool debug_on = true;
        public enum LOG_LEVEL {
            debug = 0,
            info = 1,
            warning = 2,
            error = 3,
            access = 4
        }

        DirectoryInfo profiles_obj;

        StringCollection inaccessible = new StringCollection();
        StringCollection momentaries = new StringCollection(); // Files that existed earlier but don't exist during parse.
        StringCollection copy_failures = new StringCollection();


        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
        private const int WM_VSCROLL = 277;
        private const int SB_PAGEBOTTOM = 7;
        internal static void ScrollToBottom(RichTextBox richTextBox) {
            SendMessage(richTextBox.Handle, WM_VSCROLL, (IntPtr)SB_PAGEBOTTOM, IntPtr.Zero);
            richTextBox.SelectionStart = richTextBox.Text.Length;
        }

        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {
            profiles_obj = new DirectoryInfo(@"C:\Users");
            DirectoryInfo[] profiles = profiles_obj.GetDirectories();
            //profileNameCbx.DataSource = profiles;
            foreach(DirectoryInfo profile in profiles) {
                if(
                    profile.Name != "All Users" &&
                    profile.Name != "Default" &&
                    profile.Name != "Default User" &&
                    profile.Name != "Public"
                    ) {
                    profileNameCbx.Items.Add(profile);
                }
            }
        }

        private void ProfileNameCbx_SelectedValueChanged(object sender, EventArgs e) {
            var profileDir_path = @"C:\Users\" + profileNameCbx.Text;
            if (Directory.Exists(profileDir_path)) {
                browserTV.Nodes.Clear();
                TreeNode root = browserTV.Nodes.Add(profileDir_path, profileNameCbx.Text, 0);
                ParseProfile(root);
            }
        }


        public void ParseProfile(TreeNode parent_node) {
            DirectoryInfo parent_di = new DirectoryInfo(parent_node.Name);
            FileInfo[] files = null;
            DirectoryInfo[] subDirs = null;
            try {
                files = parent_di.GetFiles("*.*").Where(file =>
                    (file.Attributes & FileAttributes.Hidden) == 0).ToArray();
            }
            catch(UnauthorizedAccessException e) {
                inaccessible.Add(parent_di.FullName);
                Log(e.Message, LOG_LEVEL.access);
            }
            catch (DirectoryNotFoundException e) {
                momentaries.Add(parent_di.FullName);
                Log(e.Message, LOG_LEVEL.warning);
            }
            catch (Exception e) {
                Log(e.Message, LOG_LEVEL.debug);
                // Throw this in the end.
            }

            if(files != null) {
                subDirs = parent_di.GetDirectories().Where(directory =>
                    (directory.Attributes & FileAttributes.Hidden) == 0).ToArray(); ;
                foreach(DirectoryInfo dir in subDirs) {
                    TreeNode this_node = parent_node.Nodes.Add(dir.FullName, dir.Name, 0);

                    // Recusive call for each subdirectory
                    ParseProfile(this_node);
                }

                foreach (FileInfo f in files) {
                    parent_node.Nodes.Add(f.FullName, f.Name, 1);
                }

                //browserTV.Refresh();
            }
        }

        public void Log(string msg, LOG_LEVEL lvl) {
            Color orig = consolRTB.SelectionColor;
            switch (lvl) {
                case LOG_LEVEL.debug:
                    if (debug_on) {
                        consolRTB.SelectionColor = Color.FromArgb(225, 226, 239);
                    }
                    break;
                case LOG_LEVEL.info:
                    consolRTB.SelectionColor = Color.FromArgb(170,246,131);
                    break;
                case LOG_LEVEL.warning:
                    consolRTB.SelectionColor = Color.FromArgb(255, 217, 125);
                    break;
                case LOG_LEVEL.error:
                    consolRTB.SelectionColor = Color.FromArgb(238, 96, 85);
                    break;
                case LOG_LEVEL.access:
                    consolRTB.SelectionColor = Color.FromArgb(145, 196, 242);
                    break;
            }
            consolRTB.AppendText(String.Concat("\n",msg,"\n"));
            consolRTB.SelectionColor = orig;
        }

        private void ConsolRTB_TextChanged(object sender, EventArgs e) {
            if (autoscrollChB.Checked) {
                ScrollToBottom(consolRTB);
            }
        }

        private void AutoscrollChB_CheckedChanged(object sender, EventArgs e) {
            if (autoscrollChB.Checked) {
                ScrollToBottom(consolRTB);
            }
        }
    }
}

Is there information about an example of a tiff file display for .net core?