https://community.appian.com/support/w/kb/473/kb-1259-portal-reports-display-blank-values-for-data-in-certain-rows-columnsen-USTelligent Community 12https://community.appian.com/support/w/kb/473/kb-1259-portal-reports-display-blank-values-for-data-in-certain-rows-columnsTue, 07 Mar 2017 14:57:23 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:7fb46076-c150-4d0d-9559-bdd817f63b11Nick Vigilantehttps://community.appian.com/support/w/kb/473/kb-1259-portal-reports-display-blank-values-for-data-in-certain-rows-columns#commentsCurrent Revision posted to Appian Knowledge Base by Nick Vigilante on 3/7/2017 2:57:23 PM<br /> <div class="row content_container"> <h2 id="symptoms">Symptoms</h2> <p>A portal report displays blank values for data in certain rows/columns.</p> <h2 id="cause">Cause</h2> <p>If these values aren&rsquo;t expected to be blank then there has been an expression evaluation error at some point. Note that even a single error has the potential to affect multiple rows or columns of data since expression evaluations for data in portal reports is done in batches.</p> <h2 id="action">Action</h2> <p>Review the <a href="https://docs.appian.com/suite/help/latest/Report_Performance_Details.html">report performance details</a> page and look for any errors, typically those that show <code>(Error)</code> in the <strong>Type</strong> column. The root cause can be identified from this message.</p> <p>An example of such an error message is:</p> <pre><code>Eval@reason=Invalid index (0) for list; valid range is empty) </code></pre> <p>This indicates that a null or zero value is passed as an array index. This can be resolved by introducing a simple null check in the column expression.</p> <h2 id="affected-versions">Affected Versions</h2> <p>This article applies to all versions of Appian.</p> </div> <p>Last Reviewed:&nbsp;March 2017</p> <div style="clear:both;"></div> <div style="font-size: 90%;">Tags: reports, application design</div>