https://community.appian.com/discussions/f/administration/11090/appian-engines-will-not-start-in-17-3I&#39;m at the early stages of upgrading an Appian environment from 17.2 to 17.3, and I&#39;m unable to start the engines. I checked the service_manager.log file, and I&#39;m receiving this error for each of the engines. The status for each engine gets stuck on STARTINGen-USTelligent Community 12https://community.appian.com/thread/48584?ContentTypeID=1Mon, 18 Sep 2017 13:04:14 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:66b69581-b68a-483b-8a28-3091396d1b99Josh BurwellThat was it, there was a newline character at the end of the file. Thank you very much for your help!<div style="clear:both;"></div>https://community.appian.com/thread/48569?ContentTypeID=1Mon, 18 Sep 2017 00:10:17 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:43a9abf4-ec8c-498e-a18d-bf24e62d367bTristan NewmannIt looks like the appian.sec security token is the incorrect length, and is causing an error when Service Manager tries to load it. <br /> <br /> Please verify the length of the token manually. It should be found in the following location: &lt;APPIAN_HOME&gt;/ear/suite.ear/conf/appian.sec<br /> <br /> The correct length for the token is 256 characters as per <a href="https://docs.appian.com/suite/help/17.3/Appian_Engine_Connection_Restrictions.html">docs.appian.com/.../Appian_Engine_Connection_Restrictions.html</a>. <br /> <br /> From the error in the stacktrace, it looks like yours is 258 characters.<div style="clear:both;"></div>