HomeOctober 2026 patch cycleKB5127648: shared printers fail with Error #87 in Settings
Call: Known issueCategory: Enterprisefrom 2026-10
Issue from: October 2026 Patch Tuesday: 1,413 fixes, one exploited zero-day, and an Exchange hangover
KB5127648: shared printers fail with Error #87 in Settings
Part of October 2026 patch cycle
- Vendor
- Microsoft
- Products
- Windows 11 24H2/25H2/26H2 (KB5127648), Windows 11 23H2, and Windows 10 22H2 ESU
- Published
- Status
- Open
Call: Known issue. After the October cumulative update, adding a printer shared from a Windows print server through Settings fails with “Error #87.” This is reported, not confirmed: about five independent reports, from Born’s blog readers and a patchmanagement.org thread. Two of them say uninstalling KB5127648 fixes it. It’s annoying, not dangerous. The manual route still works, so don’t hold October’s exploited fixes over it.
What breaks: Settings > Bluetooth & devices > Printers & scanners > Add device lists the shared printers fine, then fails with Error #87 when you pick one. Adding the same share any other way works:
- “Add manually,” by directory search or by
\\server\share rundll32 printui.dll,PrintUIEntry /im- Group Policy deployment
One admin also saw Universal Print event ID 1 errors (0xcaa2000c, 0x8086000c) on a 25H2 client at the moment the list loads.
Who’s hit: Domain-joined clients adding printers shared from Windows print servers (Server 2022 comes up). Most reports are on Windows 11 24H2 and later with KB5127648. One reader on Server 2025 and 24H2 says it works fine.
The wrinkle: One admin reproduces it on Windows 11 23H2 and Windows 10 22H2 ESU too, and first logged it on Sep 17 with the September CU (KB5122880) installed. So this may not be KB5127648 alone, and “uninstall October” may not fix every case.
Suspected cause: Born’s readers point at the NTLMv1 SSO enforcement change in KB5127648, which flipped BlockNtlmv1SSO to 1. One reader says setting it back to 0 fixed the problem. Another, whose domain has NTLMv1 turned off entirely, says it didn’t help. Nobody has confirmed this, and Microsoft hasn’t commented.
Workaround:
- Add shared printers manually (“Select a shared printer by name”) or push them by GPO. Tell the help desk before users start opening tickets.
- Treat
BlockNtlmv1SSO = 0as a diagnostic, not a fix. It reopens a legacy auth path Microsoft closed on purpose.
Sources: Born’s IT and Windows Blog (opens in a new tab) (quotes the patchmanagement.org thread), Microsoft: fix shared printer connection problems (opens in a new tab).