Unity: "Failed to load layout window" fix. See new version : https://gist.github.com/instance-id/3161cc2b5343db5bc3cef494d83a7449

unityfixlayout.ps1

#--------------------------------------------------------------------------------------------------------------
# This has been updated and changed to include several new features. See the link below for updated version: --
# https://gist.github.com/instance-id/3161cc2b5343db5bc3cef494d83a7449 ----------------------------------------
#--------------------------------------------------------------------------------------------------------------

# Replace folder paths in $projectLocations array (line 20) with your actual Unity project folder path(s)
# Usage: .\unityfixlayout.ps1 -Project MyProjectName

Param (
    [Parameter()]
    [string]$Project
)

# Checking to make sure project name and Unity version are included
if ($Project) {
    Write-Host "Fixing layout ${Project}: ${versionNumber}..."
}
else {
    Write-Host "Unity project name and version required..."
    exit
}

# Input the root folder location(s) that contain your Unity projects -----------------------
# Ex: "C:\Unity\MyProjects" : Can be multiple locations separated by comma
$projectLocations = "E:\GitHub\instance-id", "E:\_unity\_projects"
# ------------------------------------------------------------------------------------------

# Needed variables for file names and locations
$originalLayout = "Default.wlt"
$destinationLayout = "CurrentLayout-default.dwlt"
$backupLayout = "CurrentLayout-default.dwlt.bak"
$destinationLayoutPath = "\Library\${destinationLayout}" 
$versionNumber = ""

foreach ($projectFolder in $projectLocations) {
    $projectFolder = "$projectFolder\${Project}"
    
    if (Test-Path "$projectFolder") {
        # Getting Unity versionNumber from ProjectSettings
        $projectVersionLocation = "\ProjectSettings\ProjectVersion.txt"
        $destinationPath = "${projectFolder}${destinationLayoutPath}"
        $projectVersionFile = "${projectFolder}${projectVersionLocation}"
    
        Write-Host "Unity project $Project found: $projectFolder"
        Write-Host "Unity project version file found: $projectVersionFile"

        $file_data = Get-Content $projectVersionFile | Where-Object { $_ -like ‘*m_EditorVersion: *’; } 
        $separator = ": "
        $versionString = $file_data.split($separator); 
        $versionNumber = ${versionString}[1]
        
        # Default Unity hub installation folder. If yours are installed in a non-default folder please update accordingly
        $originalLayoutFile = "C:\Program Files\Unity\Hub\Editor\$versionNumber\Editor\Data\Resources\Layouts\$originalLayout"

        # Checking if provided Unity version exists in specified installation folder location
        if (Test-Path $originalLayoutFile) {
            Write-Host "Original layout file for Unity version $versionNumber found..." 
            if ([System.IO.File]::Exists($destinationPath)) {
                Write-Host "Probematic layout file found: $destinationPath"

                # Backup original layout file
                Write-Host "Creating backup of original layout file at: ${destinationPath}.bak"
                Copy-item -Force -Verbose -Path ${destinationPath} -Destination "${destinationPath}.bak"
                
                # Copy Default layout for editor version from install folder and rename to required filename
                Write-Host "Copying default layout for version $versionNumber to $Project Library..."
                Copy-item -Force -Verbose -Path $originalLayoutFile -Destination "${destinationPath}"
            }
            else {
                Write-Host "Could not locate probematic layout file at location: $destinationPath"
                Write-Host "Please check that Library folder exists at path: ${projectFolder}\Library"
            }
        }
        else { 
            "Unity $versionNumber not found"
            return;
        }
    }
}

Write-Host "Layout fix completed"
return;

This is currently only set up for Windows, but since Powershell is now cross-platform if there is any interest/need I can make it work on Linux/Mac.