Sitecore workbox Timeout only for single user

Question

There is user who uses AD to access Sitecore. Whenever he tries access the workbox he ends up getting timeout error. He can access all other tabs in Sitecore without issue.

Another user with exact same level of access and also comes from AD is able to access workbox along with all other features.

To make it even more weird we tried using the user credentials on our local by resetting the password and it throws timeout on our machines as well. The user seeing error can access other user accounts and can access workbox from the same computer. We are unsure on how to proceed with this.

Answer 1

Just to add to Dean's answer, the Workbox tool has settings that are stored in the user profile. These settings include selected workflows and number of items per page as shown in the screenshot below:

It is possible that the user selected all available workflows or changed the number of items per page to "All" and this is causing the timeout because Sitecore tries to load too many items. As these settings are stored in the database against each user profile, you can reproduce the same issue when logging in as this user from a different computer.

As a workaround, you can reset Workbox settings for this user via code or PowerShell script as described in this question:

Sitecore.Security.Authentication.AuthenticationManager.SetActiveUser(userName);
Sitecore.Web.UI.HtmlControls.Registry.SetInt("/Current_User/Workbox/Page Size", 10);

If you want to prevent this from happening in future, consider Sitecore recommendations to improve Workbox opening performance as Dean suggested. For example, limit the number of rows Sitecore can load in the Workbox by reducing this threshold:

<setting name="Workbox.SingleWorkflowStateVersionLoad.Threshold" value="100"/>

or try creating an SQL index for the Master database:

CREATE NONCLUSTERED INDEX IX_Versioned_Workflow_Filtered
    ON VersionedFields (itemid,FieldId)
    INCLUDE (Value,language,version, updated)
    WHERE FieldId='{3E431DE1-525E-47A3-B6B0-1CCBEC3A8C98}'

Answer 2

It sounds like that specific user has too many workflow tasks attributed to them. The default maximum number of items is 2000 per workflow. You can reduce this to a smaller number to make it more manageable.

Please patch in this setting:

name="Workbox.SingleWorkflowStateVersionLoad.Threshold

Reference and some other performance suggestions here: https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0879610