DRAFT KB-[SP-3014]"Unexpected token < in JSON at position 0" Error

Symptoms

Users that authenticate with SAML see the following error when navigating around Appian or interacting with an interface:

The error may also appear if one or more of the following apply:

The session timeout in Appian and the session timeout in the Identify Provider have different values.
Users are inactive in Appian for a prolonged period.
Users log out of Appian in one tab while still having Appian open in a second tab. When navigating around the second tab, they see this error.

Cause

HTML code is being evaluated directly in SAIL. This often occurs when the Appian session has timed out, and the authentication process is triggering directly in SAIL code instead of in the browser. This issue has been reported to the Appian Product Team. The reference number for this issue is AN-87093.

Workaround

Refreshing the page will resolve the error and redirect the user to the Login Page.
In some instances, setting the Identity Provider session timeout to match the Appian session timeout will reduce the occurrence of this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: July 2020