TL;DR: Print Spooler keeps stopping: “The RPC server is unavailable” (0x000006ba)

The fix only. No explanation, no diagnosis. Read the full article if any of this does not match what you are seeing.

1. Open PowerShell as administrator and check the service.

Get-Service Spooler | Select-Object Status, StartType

2. Stopped or disabled? Check that Group Policy is not disabling it on purpose, then try Restart-Service -Name Spooler.
3. Running now but jobs are stuck, or it stops again soon after starting? Clear the queue. The ready-made script asks before it does anything and supports -WhatIf: see /scripts/reset-print-spooler-powershell/

Clearing the queue deletes every queued print job on that computer, for every printer.

4. Still crashing? Find the driver: look in Event Viewer, Application log, for the faulting module in spoolsv.exe errors, and in Microsoft-Windows-PrintService/Admin. Remove or update the third-party driver named there.

Get-PrinterDriver | Select-Object Name, Manufacturer
Remove-PrinterDriver -Name "<driver name>" -WhatIf

5. Error appears only when connecting to a shared printer on another server? The spooler on your PC may be fine. Test the connection to the print server (RPC uses TCP 135 plus a high port range) and fix name resolution or the firewall there.

Do not change RPC ports or DCOM permissions to fix this on a single PC. It does not help when the spooler itself is the problem.

← Full article, with the diagnosis and the why