I want to be perfectly clear:  this article is about whether people must update to Joomla 4.x.  This article is not about whether people should update to J! 4.x, what are the benefits or problems and/or disadvantages in doing so.

If you are using J! 3.10A similar feature was added in J! 2.5.28 to “remind” people that support for this version would cease on 31-Dec-2014.  This feature could be turned off by disabling a plugin. you will have seen a notice about “End of Support” when you login.

j4Hassle2 j4Hassle3 j4Hassle4 j4Hassle5 These message escalate in severity, from benign “informational” notices, through a “warning” phase and ultimately are displayed as “errors”.Joomla 3.10: End of Support Handling  The images at the right of the screen show how those messages will appear over time, starting on 17-Aug-2021, changing every six months, until the last message will appear on 17-Aug-2023.  These messages can be temporarily hidden, by clicking the close icon located in the top right corner, these messages will reappear every time you visit the backend “home page”. The informational and warning messages can be “snoozed” by clicking the orange button but the final “error” phase cannot be snoozed.

I think it’s fair to say that one of the most baffling problems people encounter with Joomla! is when they get an unexpected fatal error that reads “Failed to start application: Failed to start the session”.  The Joomla! forum is rife with examples of this problem and, unfortunately, many people do not get always get answers that solve their problem.

My website, stopped working all in a sudden. I uploaded an article and it was working for a week and then, without any further changes, I get this message:  “Error:  Failed to start application: Failed to start the session”.  I even cannot login to my Joomla backend!forum user, Joomla Forum, 13-Sep-2020

I won’t go into technical details about what a sessionhttps://www.quora.com/What-are-internet-sessions is but it’s important; you can’t work with internet websites without some kind of session management.  Sessions are used to make sure that you get what you want and you don’t get something that someone else wants if they happen to be accessing the same page that you are accessing.  Sessions are a way of keeping your interaction with a website separate from other people who may be interacting with the website.

Joomla uses sessions.  The details about Joomla sessions are stored on the server.  There are several ways that website owners can configure Joomla to handle session management but the two most common methods are to store the session data in the database or to store the session data on a temporary file.  We will examine both methods in this article.  We will also look at some of the common causes for why people get these “failed to start the session” errors.