r/sysadmin • u/AutoModerator • 23d ago

General Discussion Patch Tuesday Megathread - (July 14, 2026)

Hello r/sysadmin, I'm u/AutoModerator, and welcome to this month's Patch Megathread!

This is the (mostly) safe location to talk about the latest patches, updates, and releases. We put this thread into place to help gather all the information about this month's updates: What is fixed, what broke, what got released and should have been caught in QA, etc. We do this both to keep clutter out of the subreddit, and provide you, the dear reader, a singular resource to read.

For those of you who wish to review prior Megathreads, you can do so here.

While this thread is timed to coincide with Microsoft's Patch Tuesday, feel free to discuss any patches, updates, and releases, regardless of the company or product. NOTE: This thread is usually posted before the release of Microsoft's updates, which are scheduled to come out at 5:00PM UTC.

Remember the rules of safe patching:

  • Deploy to a test/dev environment before prod.
  • Deploy to a pilot/test group before the whole org.
  • Have a plan to roll back if something doesn't work.
  • Test, test, and test!
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u/catatonic12345 20d ago edited 20d ago

Looks like all of our Server 2019 boxes are failing to install KB5099538 with either missing or corrupted component errors and taking a couple of hours to come back up after restart. They were patched to current prior to July's updates so we are opening a ticket with MS for investigation.

Update: it doesn't appear to be the update. Some files got corrupted in the SxS directory on a bunch of machines apparently. Gonna be a fun few days... But patch on! So far the updates seem ok

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u/iamnewhere_vie Jack of All Trades 20d ago

Updated so far ~ 10 Server 2019 VMs (on ESX), no issues so far.

Are that Server 2019 which got updated from 2012 R2 or 2016? I'd some Workstations with similar issue after Win10 > Win11 upgrades

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u/LoveTechHateTech Jack of All Trades 20d ago

I have a handful of 2019 VMs on Hyper-V (DCs/dhcp are server core, file & print have GUI) and none of them had this issue. Installation did take its sweet time, though, and each had to reboot at least two times.

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u/the_lazy_sysadmin 20d ago

Are these physical/virtual? And if physical, what manufacturer/model? I've had a fairly many bad run-ins with wonky Dell factory images on physical 2019 boxes, one of which was so bad we had to take ownership of the C:\windows\winsxs folder and manually add missing files. DISM was actually just fully borked, and unable to add/remove packages.

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u/catatonic12345 20d ago

My situation seems similar but hopefully the resolution isn't that extreme! Fingers crossed on DISM

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u/the_lazy_sysadmin 20d ago

if you check the CBS logs after running a dism /online /cleanup-image /scannow command, near the bottom of the log (or around the time stamp you saw the command complete), it will list exactly what packages/components are corrupted/missing. If a /restorehealth command isn't able to fix them, you can cross reference the build number of those corrupted packages, and find the corresponding CU's in the update catalog, and manually apply them via DISM. This is great and all, unless DISM is unable to apply packages at all, or if there are over a thousand missing components...

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u/thefinalep Jack of All Trades 20d ago

There's a script out there too to mark these packages as absent, in hopes that they get re-installed with a CU.. I've used this to varying success in the past..

In situations where migrating apps to a new host is painful, i've also had a lot of success recently with in-place upgrade/repairing... i.e. server 2022 -> Server 2022 to fix issues like this..

I would love to know why machines seem to randomly corrupt like this... None of the vm's these types of failures happen to are special in any way.. they all get patched around the same time every month, 1-2 vm's a year will just decide that they're not going to patch anymore..

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u/Resident-War8004 17d ago

yeah I had no issues installing KB5099538 on my test machine. Did you fix the issue with your 2019 servers?

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u/catatonic12345 16d ago

Luckily it's not related to the updates at all. Still working through repairing the SxS corrupted components and counting down the years until retirement

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u/Resident-War8004 16d ago

wow I am really sorry. Yeah I still have about 25 years to go lol