Why does MATLAB Web App Server fail to start with "The service did not start due to logon failure" errors in Event Viewer?

I have been using MATLAB Web App Server (Windows) for several months. Recently, I was unable to access the server and noticed that it had stopped. When I tried to manually restart it, I see the error:

MATLAB Web App Server service failed to start.

No logs were written. Check that "logs_path" is writable by the service users.

When I follow the steps in this MATLAB Answer to get more information: How can I get more information when MATLAB Web App Server fails to start with no logs or limited log information written?, I see the following error in Event Viewer: 

The MATLAB Web Apps (R2025a) service failed to start due to the following error:
The service did not start due to logon failure.

How can I resolve this issue?

Answer 1

[MathWorks Support Team]

This error typically indicates that the passwords for the service accounts used by MATLAB Web App Server have expired. 

By default, MATLAB Web App Server will create two service accounts to run the server and worker processes. These accounts have the default usernames specified here, and auto-generated passwords. Depending on your organization's password policy, these passwords my automatically expire after some period of time, which will prevent the services from running until their credentials have been updated.  

To resolve this, you will need to reset the passwords for the service accounts (and set them to never expire), then update the credentials for the MATLAB Web App Server services with these new credentials:

1. Type Win+R to open the "Run" console, and enter "lusrmgr.msc" to open the Local Users and Groups management:
   
2. From the Users, locate the two service accounts for your version of MATLAB Web App Server. For example, for R2025a:
   
3. For each service, right-click the service and select "Set Password..." to set a new password for the service account:
   
4. [Optional] To prevent the passwords from expiring again, right-click each service and select Properties, then check the "Password never expires" checkbox: 
   
5. To update the credentials for the associated services to use the new passwords, see the following MATLAB Answer: https://www.mathworks.com/matlabcentral/answers/456956-how-can-i-update-the-credentials-for-the-matlab-web-app-server-service-accounts