That is what I meant by bad usage of conversation, propagation=none means it will not send the conversation Id and if there is long running conversation from previous state, it will be reset /set to null/

Random IllegalArgumentException: Stack must not be null ------------------------------------------------------- Key: JBSEAM-5143 URL: https://issues.jboss.org/browse/JBSEAM-5143 Project: Seam 2 Issue Type: Bug Components: Core Affects Versions: 2.3.1.Final Reporter: Robert Becker Since upgrading to Seam 2.3 with Mojarra 2.1.29 on glassfish v3 from Seam 2.2.2, I get random IllegalArgumentExceptions with the message "Stack must not be null". The application worked fine for several years until now. The full stack trace is listed here: http://pastebin.com/RjLndvnE The exception randomly happens (in about 1 of 500 requests) when navigating between pages, submitting forms, switching (RichFaces) tabs and so on. I believe restarting glassfish and/or enabling client side state saving reduces the frequency of the issue whereas it seems to happen more often after multiple successive redeployments during development. Sadly, due to several dependencies this is already in production but happens far less often there, but it still happens daily according to the server logs. I have also posted this on stackoverflow (http://stackoverflow.com/questions/27107870/seam-2-3-illegalargumentexcep...) but have not received any answers yet. Besides Seam 2.3, the following libraries are used: - Mojarra 2.1.29 - RF 4.5 (exception also occurred with 4.3.x) - Omnifaces 1.10RC1 (will upgrade to 2.0) - Primefaces 5.1