Event ID 2005: ECP Fails to Load - Fix Guide 2025

Log Name:      Application
Source:        MSExchange Control Panel
Event ID:      2005
Level:         Error
Description:   ECP could not be initialized because of an error.
               Exception: System.Configuration.ConfigurationErrorsException:
               Could not load file or assembly 'Microsoft.Exchange.Management.ControlPanel'
               or one of its dependencies. The system cannot find the file specified.
               Stack trace:
               at Microsoft.Exchange.Management.ControlPanel.Application.Start()

Import-Module WebAdministration

# Restart the pool
Restart-WebAppPool -Name "MSExchangeECPAppPool"
Write-Host "ECP app pool restarted"

# Wait and verify
Start-Sleep -Seconds 10

$state = (Get-WebAppPoolState "MSExchangeECPAppPool").Value
if ($state -eq "Started") {
    Write-Host "App pool running" -ForegroundColor Green
} else {
    Write-Host "App pool state: $state" -ForegroundColor Red
}

# Test ECP
try {
    $response = Invoke-WebRequest -Uri "https://localhost/ecp/" -UseBasicParsing -TimeoutSec 30
    Write-Host "ECP responding: $($response.StatusCode)" -ForegroundColor Green
} catch {
    Write-Host "ECP still failing" -ForegroundColor Red
}

# Full IIS service restart
iisreset /noforce

Write-Host "Waiting for services..."
Start-Sleep -Seconds 20

# Verify all Exchange pools running
Import-Module WebAdministration
Get-ChildItem IIS:\AppPools | Where-Object {$_.Name -like "*Exchange*"} |
  Select-Object Name, State | Format-Table

# Quick ECP test
Test-EcpConnectivity | Select-Object Scenario, Result -First 1

# Stop IIS first
iisreset /stop

# Clear .NET temporary compilation files
$tempPaths = @(
    "$env:windir\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files"0.30319\Temporary ASP.NET Files",
    "$env:LOCALAPPDATA\Temp\Temporary ASP.NET Files"
)

foreach ($path in $tempPaths) {
    if (Test-Path $path) {
        Remove-Item "$path\*" -Recurse -Force -ErrorAction SilentlyContinue
        Write-Host "Cleared: $path"
    }
}

# Restart IIS
iisreset /start

Write-Host "ASP.NET temp files cleared, IIS restarted"

# Document current settings
Get-EcpVirtualDirectory | Format-List * | Out-File "C:\Temp\ECP-Backup.txt"

# Remove existing virtual directory from Exchange
Get-EcpVirtualDirectory -Server $env:COMPUTERNAME | Remove-EcpVirtualDirectory -Confirm:$false

# Remove from IIS if still present
Import-Module WebAdministration
$iisEcp = Get-WebApplication -Site "Default Web Site" -Name "ecp" -ErrorAction SilentlyContinue
if ($iisEcp) {
    Remove-WebApplication -Site "Default Web Site" -Name "ecp"
    Write-Host "Removed from IIS"
}

# Create new virtual directory
New-EcpVirtualDirectory -Server $env:COMPUTERNAME -WebSiteName "Default Web Site"

# Configure URLs (adjust to match your environment)
$internalUrl = "https://mail.company.com/ecp"
$externalUrl = "https://mail.company.com/ecp"

Get-EcpVirtualDirectory -Server $env:COMPUTERNAME |
  Set-EcpVirtualDirectory -InternalUrl $internalUrl -ExternalUrl $externalUrl

# Configure authentication
Get-EcpVirtualDirectory -Server $env:COMPUTERNAME |
  Set-EcpVirtualDirectory -FormsAuthentication $true

# Reset IIS
iisreset /noforce

Write-Host "ECP virtual directory recreated" -ForegroundColor Green

# If ECP files are missing, repair Exchange installation

# Option 1: Run CU in upgrade mode (recommended)
$cuPath = "D:\ExchangeUpdates\ExchangeServer2019-CU14.exe"  # Adjust path

# This repairs all virtual directories and restores files
& $cuPath /mode:upgrade /IAcceptExchangeServerLicenseTerms

# Option 2: PrepareAD can sometimes fix AD-based configs-based configs
# & $cuPath /PrepareAD /IAcceptExchangeServerLicenseTerms

# After repair, verify ECP
Test-EcpConnectivity | Format-Table Scenario, Result

Import-Module WebAdministration

# Remove existing pool if broken
$pool = Get-Item IIS:\AppPools\MSExchangeECPAppPool -ErrorAction SilentlyContinue
if ($pool) {
    Stop-WebAppPool "MSExchangeECPAppPool" -ErrorAction SilentlyContinue
    Remove-WebAppPool "MSExchangeECPAppPool"
    Write-Host "Removed existing app pool"
}

# Create new pool with correct settings
New-WebAppPool -Name "MSExchangeECPAppPool"

$poolPath = "IIS:\AppPools\MSExchangeECPAppPool"
Set-ItemProperty $poolPath -Name managedRuntimeVersion -Value "v4.0"
Set-ItemProperty $poolPath -Name managedPipelineMode -Value "Integrated"
Set-ItemProperty $poolPath -Name processModel.identityType -Value "LocalSystem"
Set-ItemProperty $poolPath -Name startMode -Value "AlwaysRunning"

# Configure recycling
Set-ItemProperty $poolPath -Name recycling.periodicRestart.time -Value ([TimeSpan]::Zero)
Set-ItemProperty $poolPath -Name recycling.periodicRestart.schedule -Value @{value="03:00:00"00:00"}

# Assign to ECP application
Set-ItemProperty "IIS:\Sites\Default Web Site\ecp" -Name applicationPool -Value "MSExchangeECPAppPool"

# Start pool
Start-WebAppPool "MSExchangeECPAppPool"

Write-Host "ECP app pool recreated" -ForegroundColor Green

# Reset permissions on ECP folder
$ecpPath = "$env:ExchangeInstallPath\ClientAccess\ecp"

# Reset to inherited
icacls $ecpPath /reset /t /c

# Add required permissions
$acl = Get-Acl $ecpPath

# IIS_IUSRS
$rule1 = New-Object System.Security.AccessControl.FileSystemAccessRule(
    "IIS_IUSRS", "ReadAndExecute", "ContainerInherit,ObjectInherit", "None", "Allow")
$acl.AddAccessRule($rule1)

# NETWORK SERVICE
$rule2 = New-Object System.Security.AccessControl.FileSystemAccessRule(
    "NETWORK SERVICE", "ReadAndExecute", "ContainerInherit,ObjectInherit", "None", "Allow")
$acl.AddAccessRule($rule2)

# LOCAL SYSTEM
$rule3 = New-Object System.Security.AccessControl.FileSystemAccessRule(
    "SYSTEM", "FullControl", "ContainerInherit,ObjectInherit", "None", "Allow")
$acl.AddAccessRule($rule3)

Set-Acl $ecpPath $acl

Write-Host "Permissions reset on ECP folder"

# Restart IIS
iisreset /noforce

# 1. Test ECP connectivity
Test-EcpConnectivity -ClientAccessServer $env:COMPUTERNAME |
  Select-Object Scenario, Result, Latency, Error | Format-Table

# 2. Test URL directly
$urls = @(
    "https://localhost/ecp/",
    "https://localhost/ecp/default.aspx"
)

foreach ($url in $urls) {
    try {
        $response = Invoke-WebRequest -Uri $url -UseBasicParsing -TimeoutSec 30 -MaximumRedirection 0
        Write-Host "$url - $($response.StatusCode)"$response.StatusCode)" -ForegroundColor Green
    } catch {
        $status = $_.Exception.Response.StatusCode.value__
        if ($status -eq 302) {
            Write-Host "$url - 302 (redirect to login - OK)"302 (redirect to login - OK)" -ForegroundColor Green
        } else {
            Write-Host "$url - $status"$status" -ForegroundColor Red
        }
    }
}

# 3. Verify no new 2005 errors2005 errors
$since = (Get-Date).AddMinutes(-15)
$errors = Get-WinEvent -FilterHashtable @{
    LogName = 'Application'
    ProviderName = 'MSExchange Control Panel'
    Id = 2005
    StartTime = $since
} -ErrorAction SilentlyContinue

Write-Host "`nEvent 2005 errors in last 15 min: $($errors.Count)"15 min: $($errors.Count)"

# 4. Check app pool health
Import-Module WebAdministration
$pool = Get-Item IIS:\AppPools\MSExchangeECPAppPool
Write-Host "App pool state: $($pool.State)"

# Schedule this weekly
$result = Test-EcpConnectivity -ClientAccessServer $env:COMPUTERNAME

$success = ($result | Where-Object {$_.Result -eq "Success"}).Count
$total = $result.Count

if ($success -lt $total) {
    $body = "ECP Health Check Failed`n"
    $body += ($result | Format-Table | Out-String)

    Send-MailMessage -To "admin@company.com" -From "monitor@company.com" -Subject "ECP Health Alert" -Body $body -SmtpServer localhost
} else {
    Write-Host "ECP health: $success/$total tests passed"$total tests passed"
}

# Run after every CU installation
Write-Host "Post-CU ECP Verification" -ForegroundColor Cyan

# Check virtual directory
$ecp = Get-EcpVirtualDirectory
if ($ecp) {
    Write-Host "ECP VDir: OK" -ForegroundColor Green
} else {
    Write-Host "ECP VDir: MISSING" -ForegroundColor Red
}

# Test connectivity
$result = Test-EcpConnectivity | Select-Object -First 1
Write-Host "Connectivity: $($result.Result)"

# Check app pool
Import-Module WebAdministration
$pool = (Get-WebAppPoolState "MSExchangeECPAppPool").Value
Write-Host "App Pool: $pool"