After installing January-26 patch KB 5002825 KB 5002823 getting access denied error on Sharepoint 2019

@Teddie-D Thanks for prompt response. I have single server and psconfig.exe run successfully without error.

I did issreset and timerservice restarted.

I checked built verison on server using powershell and it is showing as below

I am getting error like below :-

/_layouts/15/AccessDenied.aspx?Source=https%3A%2F%2Fhome%2EABC%2Ecom&correlation=<removed>

Central Admin is working as expected and i checked iis and alternate access mapping all are having same configuration. DB access is also available.

Hi @Bhushan Borole 
Thank you for your response.
Since PSConfig.exe completed without errors on your single‑server farm, the patch is correctly applied at both the binary and schema level. The fact that Central Administration remains accessible while content sites return Access Denied on /_layouts/15/AccessDenied.aspx points to an authorization inconsistency within the content web application rather than a farm‑wide patch issue. Central Admin runs in its own web application and relies on farm‑level permissions, which explains why it continues to function. 

Here are some steps you may try: 

1.Web Application User Policy  

In some cases, security updates can expose or enforce existing Web Application policies. 

Go to  Central Administration > Application Management > Manage Web Applications > Select the affected web application > User Policy 

Verify that: 

-There is no Deny policy applied 

-There is no policy applied to “All Users” that restricts access 

-Your account is not explicitly restricted 

A Deny policy at the Web Application level overrides all site permissions. 

2.Configuration cache inconsistency 

Even after PSConfig runs successfully, the configuration cache can become out of sync. A full rebuild often resolves this: 

-Stop the SharePoint Timer Service (SPTimerV4). 

-Navigate to the configuration cache folder: C:\ProgramData\Microsoft\SharePoint\Config (hidden folder). 

-Open the GUID-named subfolder (usually only one). 

-Delete all XML files inside it except cache.ini (do not delete cache.ini). 

-Open cache.ini in Notepad and set its value to 1 

-Save the file. 

-Start the SharePoint Timer Service. 

-Wait 1–2 minutes for the cache to rebuild. 

-Run: iisreset 

-Test the site again. 

3.Permission inheritance or library issues 

Some security updates tighten permission enforcement, which can expose previously unnoticed ACL inconsistencies (e.g., Master Page Gallery, Style Library, or hidden system lists). 

-If you can access the site after assigning yourself as Site Collection Administrator, go to: Site Settings > Site Permissions > Check Permissions > Enter your account and review the reported effective permissions. 

Please note that being a farm administrator does not automatically grant Site Collection Administrator rights.  

-If the site loads but certain pages fail, verify permissions on: 

• Master Page Gallery https://home.ABC.com/_catalogs/masterpage/Forms/AllItems.aspx 
• Style Library 
• Site Assets 

Ensure inheritance is intact and that your administrative account has Full Control. 

Hi @Bhushan Borole 
Is there any update on this thread?
If you need further assistance, please feel free to let us know. Thank you!

Hi @Austin-H , i tried all the steps mentioned above and issue is still persist.

Hi Bhushan Borole
Thanks for your response. Could you provide a screenshot of your Web Application Policy looks like?

Please also use ULS Viewer to check on the log on your server if the issue happens along with Correlation ID, the log location should look like this:

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\LOGS
I also sent a private message to you on this, please check it and reply to me with additional information.