WSUS synchronisation issue

Question

WSUS synchronisation issue

matteu31 512

Hello,

I try to build a new WSUS server today and it's not working during the step "Connect to upstram server".

2026-05-13_17h24_26

I'm using Microsoft Update and the wizzard is stucked here since more than 30 min...

When I go to the logs on the C:\program\update services\logs\Softwaredistribution.log

I have lot's lot's lot's of these entries :

DBConnection.ExecuteCommandNoResult SqlException occurred. Number 50000 and message invalid update identity (AtLeastOne Prerequisite) in XML for update {update GUID}

I test on Windows server 2019 / 2022 / 2025 and all have the same issue.

Is there a known issue now ?

Martin Z 5 Reputation points

2026-05-16T16:03:59.3433333+00:00

Got the exact same issue on a configMgr. Tried several servers now in a testlab. I'm getting a couple more products than the initial ones but no Windows Server past 2019, no Devtools and no Win 11 except DUs. Powershell sync-CMSoftwareUpdate didn't help even with full sync. About 5000 sql Errors per sync cycle in Softwaredistribution.log while the MECM logs are clean and report canceled sync as success. This plagues me about 2 weeks now.

2 answers

Your answer

Martin Z 5 Reputation points

2026-05-16T16:03:59.3433333+00:00

Got the exact same issue on a configMgr. Tried several servers now in a testlab. I'm getting a couple more products than the initial ones but no Windows Server past 2019, no Devtools and no Win 11 except DUs. Powershell sync-CMSoftwareUpdate didn't help even with full sync. About 5000 sql Errors per sync cycle in Softwaredistribution.log while the MECM logs are clean and report canceled sync as success. This plagues me about 2 weeks now.

Answer 1

Brian Huynh 3,045 Microsoft External Staff Moderator

Hello matteu31, thank you for posting in the Microsoft Q&A community.

The error SqlException occurred. Number 50000 and message invalid update identity (AtLeastOne Prerequisite) in XML for update means that WSUS is attempting to parse update metadata (XML) downloaded from Microsoft Update and insert it into the local SUSDB database, but the SQL stored procedure is rejecting it due to a malformed prerequisite schema.

Because you have replicated this exact failure across clean installations of Windows Server 2019, 2022, and 2025, this indicates a transient server-side issue on Microsoft's end. A recently published update on the Microsoft Update catalog likely contains malformed XML metadata. When your new WSUS server attempts its initial catalog sync to discover available products, it pulls this broken metadata, causing the local database transaction to fail and halting the wizard.

Since the GUI Configuration Wizard can get permanently stuck when encountering a catalog exception, bypassing the wizard and forcing the synchronization through PowerShell can handle the exception more gracefully or skip the problematic metadata block.

Click Cancel to close the WSUS Configuration Wizard.
Open an elevated PowerShell prompt and run the following commands to initiate a sync manually:

$wsus = Get-WsusServer
$wsus.GetSubscription().StartSynchronization()

Open the WSUS Administration Console and navigate to the Synchronizations node to monitor the progress. If it succeeds, you can then manually navigate to Options > Products and Classifications to configure your server.

Martin Z 5 Reputation points

2026-05-16T16:08:30.63+00:00

Missed the line, my above comment was supposed to land here. I was beginning to suspect unsufficient rights for the system account but manually adding the system account as webservice in SQL SUSDB didn't help either.
matteu31 512 Reputation points

2026-05-16T17:31:24.5366667+00:00

@Martin Z

Yes, I guess there is an issue because it's not a normal behavior...

Then, I can see for the first time some error on my client to download content from the WSUS server with the message "unable to find ressources".

It's on a new WSUS with new download content (and download is finish).

I think there are some issues with WSUS :/
Martin Z 5 Reputation points

2026-05-16T17:54:01.2066667+00:00

It's deprecated. But at least it's still supposed to work with configmgr (and probably should still work standalone regardless). And it does for others. There must be some detail I'm missing I can't figure out.
Adam J. Marshall 10,786 Reputation points MVP

2026-05-16T18:14:17.72+00:00

WSUS is NOT deprecated. It is end of development. BIG difference. WSUS is 100% fully supported in all aspects until at least 2035.

It is likely having an issue. Can't confirm as I'm not in front of a computer right now.
Adam J. Marshall 10,786 Reputation points MVP

2026-05-16T18:18:11.9066667+00:00

I would normally ask what products and classifications are selected as that may make a difference but if you are having trouble doing the initial metadata sync to get the list of products, then likely Microsoft is having an issue. Where are you located and what server OS version are you attempting with and is it on the latest cumulative update?
Martin Z 5 Reputation points

2026-05-17T07:29:16.13+00:00

I tried it several times on Server 2022 and 2025, fully patched, SQL with latest CU. I'm located in Germany but that shouldn't matter as another server from a collegue managed to work fine during the same period of tests. Problem is, we follow the same internal best practice. "WSUS is NOT deprecated. It is end of development." that's the definition of depecated - no longer in developement. But I think it needs an update ;)
Adam J. Marshall 10,786 Reputation points MVP

2026-05-18T13:51:30.7866667+00:00

Just set one up this morning on 2025, it downloaded within 1 hour (I left the computer for an hour, so I don't know how long it actually took) and showed me the next steps for downloading the languages and choosing products.

This is from Canada - the reason I ask because perhaps it's geographical with the issue being in the EU MS servers.
matteu31 512 Reputation points

2026-05-19T08:37:47.64+00:00

Hello,

The issue I had first was with this initial sync yes and it took arround 1 hour.

Now, this is how it looks like...

It works fine on some computer and for other it's download failed :/

and when I go to a computer from WSUS this is the reason

It's working for some and not working for other...

This is for an old update but I have the same error on recents too. Both server are on the same network.

Then, I connect manually to the server and execute a search update (to the WSUS and not Microsoft update) to install them and it worked...

Hard to understand :(

The GPO configured are :

@Adam J. Marshall Do you have an idea maybe ^^ ?

Thanks for your help
Adam J. Marshall 10,786 Reputation points MVP

2026-05-19T12:27:22.1766667+00:00

Do you have the correct mimetypes for UUP?

https://www.ajtek.ca/guides/how-to-prepare-for-on-prem-wsus-uup-updates/

If you have a licence for WAM (full disclosure, our product), it would tell you what optimizations you're missing and that also includes UUP mimetypes, the required SchUseCrypto settings, indexing, storecd procedure optimizations, and others.

If this is on server 2025, and the clients are older you may need the SelfUpdate folder still (security hardening removed this in 2025, but it still plays a role with older OSs and you may need to put it back).
matteu31 512 Reputation points

2026-05-19T12:51:26.6933333+00:00

@Adam J. Marshall

Thanks for your answer.

The server is 2019 then the only steps I do are the customization on value for IIS (memory, queue length, ...) and the SQL script for reindexation.

I don't update the mimetype for UUP but I checked and they are OK because they are added with an update and my WSUS server is up to date.

When I look the devices with error there are 2 reasons :

-(Unable to Find Resource:) ReportingEvent.Client.167

-Error: Download failed.
Adam J. Marshall 10,786 Reputation points MVP

2026-05-19T15:13:57.8966667+00:00

Yes, UUP requires the mimetype fixes, but like you said, they are ok because they were added with a CU in the past (but always good to check because I've seen where the mimetypes are not added even though the WSUS server itself is up to date).

Have you tried a wsusutil reset?

https://www.ajtek.ca/wsus/what-does-a-wsusutil-reset-do-and-when-should-i-run-a-wsusutil-reset/
Martin Z 5 Reputation points

2026-05-19T15:26:10.2666667+00:00

I built another Testserver today and just used WSUS this time. No fancy ConfigMGR stuff and was able to replicate the issue. The more I spend time with this the more I think Brian above is right. There's something rotten with EU-Servers atm. The servers connect fine to Microsoft Update but WSUS fails to insert the Metadata. Either there is an inconsistency with WSUS and SQL 2022 atm or EU-Servers' Metadata suck. Adams posts points to the latter.
matteu31 512 Reputation points

2026-05-19T17:20:18.51+00:00

@Adam J. Marshall

I tried wsusutil reset too but it's not better.

It's working fine on some computer so I don't think it's metadata issue right ?

@Martin Z

Yes, it's strange...

On my side, I just use Windows 2019 + WID
Martin Z 5 Reputation points

2026-05-21T15:23:31.8+00:00

@matteu31 I no longer think we have the same issue then ;) Allthough I suspect it's related simple because the terrible amount of garbage info WSUS provides during initial sync. My WSUS system finally got the expected updates after several hours past my work time. My Problem is ConfigManager seemingly won't allow WSUS to sync longer than 15 min before the sync gets cancelt because of all the insert failures in SQL. I synced via WSUS Console on a configMgr System and finally I saw the expected products in ConfigMgr as well. It's still syncing now so I will know tommorow or next week if I can finally distribute Updates or not. If I encounter a similar Problem with testclients as you afterwards I'll let you know.

Answer 2

matteu31 512

ok it's strange but finally it works after maybe more than 1 hour...

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WSUS synchronisation issue

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