[How to upgrade SCCM 2012 R2 SP1 to SCCM 1511 and MDT 2013?]

And, if you have drivers in the bootimages you should export them first so you have some clue of what to import in the new bootimages...

 

http://www.snowland.se/2015/09/03/export-import-boot-image-drivers-needed-before-adk-upgrade/

[SCCM 1511 DRIVER MIGRATION FAILS]

I can confirm that this issue exists and the workaround works perfect.

 

Currently migrating from CM12 to 1511 and we did some cleanup of categories before starting the migration...

Did a somewhat ugly hack to find all ID's from the logfile...

$instanceIDs = @()
$logFilePath = "C:\Program Files\Microsoft Configuration Manager\Logs\migmctrl.log"
Get-Content -Path $logFilePath | ForEach-Object {

    $s = $_
    if ($s -like "*Couldn't find the specified instance SMS_CategoryInstance.CategoryInstance_UniqueID='DriverCategories:*") {
        $s = $s.Trim() + "'~~"
        $s = $s.Substring($s.IndexOf("CategoryInstance_UniqueID='DriverCategories:") +  45)
        $s = $s.Substring(0, $s.IndexOf("'"))
        $instanceIDs += $s
    }

}

$instanceIDs | Sort-Object -Unique