Configure CMS user interface

Iframe response timeout

The PreviewTimeout setting controls how long the editing iframe waits for a response before showing an error.

If this message appears in the edit view, the response timeout for the editing iframe has been exceeded:

Preview Unavailable

Failed to load the preview within the given time constraints.

The default preview load time is 15 seconds. Increase it by adding PreviewTimeout in appSettings.json. The value is in milliseconds.

To set the preview timeout to 20 seconds, add this configuration:

{
  "EPiServer": {
    "CmsUI": {
      "UI": {
        "PreviewTimeout": 20000
      }
    }
  }
}

ApprovalStepRoleUserLimit configuration

The ApprovalStepRoleUserLimit setting helps prevent performance issues when large user groups are used in content approvals.

Large user groups in content approvals risk performance issues due to the high number of notifications in the system. The ApprovalStepRoleUserLimit app setting triggers a validation warning when an administrator adds a group with members exceeding this limit. It also limits the number of notifications sent to users in the group. The default is 100 users per group, but it is configurable:

{
  "EPiServer": {
    "CmsUI": {
      "UI": {
        "ApprovalStepRoleUserLimit": 100
      }
    }
  }
}