https://community.appian.com/support/w/kb/239/kb-1013-there-was-an-error-in-an-expression-in-null-at-null-null-error-thrown-attempting-to-publish-a-process-modelen-USTelligent Community 12https://community.appian.com/support/w/kb/239/kb-1013-there-was-an-error-in-an-expression-in-null-at-null-null-error-thrown-attempting-to-publish-a-process-modelFri, 10 Feb 2017 15:45:50 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:0194702f-797b-423e-a6fc-1b4cabd45405Nick Vigilantehttps://community.appian.com/support/w/kb/239/kb-1013-there-was-an-error-in-an-expression-in-null-at-null-null-error-thrown-attempting-to-publish-a-process-model#commentsCurrent Revision posted to Appian Knowledge Base by Nick Vigilante on 2/10/2017 3:45:50 PM<br /> <div class="row content_container"> <h2 id="symptoms">Symptoms</h2> <p>When users attempt to publish a process model, they are shown the following validation error:</p> <pre>There was an error in an expression in null at null: null </pre> <p>No error is produced in the logs.</p> <h2 id="cause">Cause</h2> <p>The process model is referencing a deleted object within an expression. The most common root cause is a swim lane pointing to a deleted process variable, deleted constant, or deleted group.</p> <h2 id="action">Action</h2> <p>Map the process model object to an existing item (e.g. fix the assignment lane).</p> <h2 id="affected-versions">Affected Versions</h2> <p>This article applies to Appian 7.8 and later.</p> </div> <p>Last Reviewed:&nbsp;February 2017</p><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: process modeler, process models, application design</div>