# Browser shows:
- Blank white page at https://mail.domain.com/owa
- Blank page at https://mail.domain.com/ecp
- Page loads but shows no content
- Partial loading with missing elements

# Event Log shows:
Log Name:      Application
Source:        MSExchange Front End HTTP Proxy
Event ID:      15021
Level:         Error
Description:   The proxy was unable to process the request.

# Import IIS module
Import-Module WebAdministration

# Check Exchange app pool states
Get-WebAppPoolState -Name "MSExchangeOWAAppPool"
Get-WebAppPoolState -Name "MSExchangeECPAppPool"
Get-WebAppPoolState -Name "MSExchangeServicesAppPool"

# List all Exchange-related app pools
Get-ChildItem IIS:\AppPools | Where-Object { $_.Name -like "*Exchange*" } |
    Select-Object Name, State | Format-Table -AutoSize

# Quick tests to isolate the issue:
# 1. Try Chrome Incognito or Edge InPrivate mode
# 2. Clear browser cache completely
# 3. Test from different workstation
# 4. Test from the Exchange server itself (localhost)

# If localhost works but remote doesn't = network/certificate issue
# If incognito works = browser cache issue
# If nothing works = server configuration issue

# Check OWA virtual directory configuration
Get-OwaVirtualDirectory | Select-Object Server, InternalUrl, ExternalUrl |
    Format-Table -AutoSize

# Check ECP virtual directory
Get-EcpVirtualDirectory | Select-Object Server, InternalUrl, ExternalUrl |
    Format-Table -AutoSize

# Test virtual directory authentication
Get-OwaVirtualDirectory | Select-Object Server, *Authentication* |
    Format-List

# Import IIS module
Import-Module WebAdministration

# Check all Exchange app pools
$appPools = @(
    "MSExchangeOWAAppPool",
    "MSExchangeECPAppPool",
    "MSExchangeServicesAppPool",
    "MSExchangeAutodiscoverAppPool"
)

foreach ($pool in $appPools) {
    $state = Get-WebAppPoolState -Name $pool -ErrorAction SilentlyContinue
    $config = Get-ItemProperty "IIS:\AppPools\$pool" -ErrorAction SilentlyContinue
    Write-Host "$pool : $($state.Value) - .NET: $($config.managedRuntimeVersion)"$state.Value) - .NET: $($config.managedRuntimeVersion)"
}

# Check for recent app pool crashes
Get-WinEvent -FilterHashtable @{
    LogName = 'System'
    ProviderName = 'WAS'
    StartTime = (Get-Date).AddHours(-24)
} -MaxEvents 10 -ErrorAction SilentlyContinue |
    Select-Object TimeCreated, Message | Format-Table -Wrap

# In browser, press F12 to open Developer Tools
# Go to Console tab - look for JavaScript errors
# Go to Network tab - look for failed (red) requests

# Common error patterns:
# - 404 errors for .js or .css files = missing files or wrong paths
# - 403 errors = permission issues
# - CORS errors = cross-origin configuration problem
# - Mixed content warnings = HTTP resources on HTTPS page

# Step 1: Recycle all Exchange app pools
Import-Module WebAdministration
$pools = @("MSExchangeOWAAppPool", "MSExchangeECPAppPool")
foreach ($pool in $pools) {
    Write-Host "Recycling $pool..."
    Restart-WebAppPool -Name $pool
}

# Step 2: Instruct users to clear browser cache
# Chrome: Ctrl+Shift+Delete -> Clear browsing data
# Edge: Ctrl+Shift+Delete -> Clear browsing data
# Firefox: Ctrl+Shift+Delete -> Clear recent history

# Step 3: Test with Ctrl+F5 (force refresh) in browser
Write-Host "Test OWA with Ctrl+F5 to bypass cache"

# Get current OWA configuration first
$owaConfig = Get-OwaVirtualDirectory -Server $env:COMPUTERNAME
$owaConfig | Select-Object InternalUrl, ExternalUrl | Format-List

# Remove existing OWA virtual directory
Remove-OwaVirtualDirectory -Identity "$($env:COMPUTERNAME)\owa (Default Web Site)" -Confirm:$false

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

# Set URLs (adjust to your environment)
Set-OwaVirtualDirectory -Identity "$($env:COMPUTERNAME)\owa (Default Web Site)" -InternalUrl "https://mail.domain.com/owa" -ExternalUrl "https://mail.domain.com/owa"

# Recycle app pool
Restart-WebAppPool -Name "MSExchangeOWAAppPool"

Write-Host "OWA virtual directory recreated. Test in 60 seconds."

# Get current ECP configuration
$ecpConfig = Get-EcpVirtualDirectory -Server $env:COMPUTERNAME
$ecpConfig | Select-Object InternalUrl, ExternalUrl | Format-List

# Remove existing ECP virtual directory
Remove-EcpVirtualDirectory -Identity "$($env:COMPUTERNAME)\ecp (Default Web Site)" -Confirm:$false

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

# Set URLs
Set-EcpVirtualDirectory -Identity "$($env:COMPUTERNAME)\ecp (Default Web Site)" -InternalUrl "https://mail.domain.com/ecp" -ExternalUrl "https://mail.domain.com/ecp"

# Recycle app pool
Restart-WebAppPool -Name "MSExchangeECPAppPool"

Write-Host "ECP virtual directory recreated. Test in 60 seconds."

# Stop IIS and all dependent services
Write-Host "Stopping IIS..."
iisreset /stop

# Clear temporary ASP.NET files
$tempPaths = @(
    "$env:SystemRoot\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files"0.30319\Temporary ASP.NET Files",
    "$env:SystemRoot\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files"0.30319\Temporary ASP.NET Files"
)
foreach ($path in $tempPaths) {
    if (Test-Path $path) {
        Write-Host "Clearing $path..."
        Remove-Item "$path\*" -Recurse -Force -ErrorAction SilentlyContinue
    }
}

# Start IIS
Write-Host "Starting IIS..."
iisreset /start

# Verify Exchange services
Get-Service MSExchangeOWA*, MSExchangeECP* | Select-Object Name, Status

# Check current SSL bindings
Import-Module WebAdministration
Get-WebBinding -Name "Default Web Site" | Where-Object { $_.protocol -eq "https" } |
    Select-Object protocol, bindingInformation, certificateHash | Format-Table

# Get Exchange certificate thumbprint
$cert = Get-ExchangeCertificate | Where-Object { $_.Services -match "IIS" }
Write-Host "Exchange IIS Certificate: $($cert.Thumbprint)"

# If binding is missing or wrong, rebind
# Remove old binding
Remove-WebBinding -Name "Default Web Site" -Protocol https -Port 443

# Add correct binding with certificate
New-WebBinding -Name "Default Web Site" -Protocol https -Port 443 -HostHeader "" -IPAddress "*"

# Bind certificate
$binding = Get-WebBinding -Name "Default Web Site" -Protocol https
$binding.AddSslCertificate($cert.Thumbprint, "My")

Write-Host "SSL binding updated. Restart IIS..."
iisreset

# Test OWA internal URL
$owaUrl = (Get-OwaVirtualDirectory).InternalUrl.AbsoluteUri
Write-Host "Testing OWA: $owaUrl"
$owaTest = Invoke-WebRequest -Uri $owaUrl -UseBasicParsing -TimeoutSec 30
Write-Host "OWA Status: $($owaTest.StatusCode)"

# Test ECP internal URL
$ecpUrl = (Get-EcpVirtualDirectory).InternalUrl.AbsoluteUri
Write-Host "Testing ECP: $ecpUrl"
$ecpTest = Invoke-WebRequest -Uri $ecpUrl -UseBasicParsing -TimeoutSec 30
Write-Host "ECP Status: $($ecpTest.StatusCode)"

# Check for recent errors
Get-WinEvent -FilterHashtable @{
    LogName = 'Application'
    ProviderName = 'MSExchange*'
    Level = 2
    StartTime = (Get-Date).AddMinutes(-15)
} -MaxEvents 5 -ErrorAction SilentlyContinue |
    Select-Object TimeCreated, ProviderName, Message | Format-Table -Wrap

# Add to scheduled task for monitoring
$urls = @(
    "https://mail.domain.com/owa/healthcheck.htm",
    "https://mail.domain.com/ecp/healthcheck.htm"
)

foreach ($url in $urls) {
    try {
        $response = Invoke-WebRequest -Uri $url -UseBasicParsing -TimeoutSec 10
        if ($response.StatusCode -eq 200) {
            Write-Host "[OK] $url" -ForegroundColor Green
        }
    } catch {
        Write-Host "[FAIL] $url - $($_.Exception.Message)"$_.Exception.Message)" -ForegroundColor Red
        # Send alert here
    }
}