Justin Rundle wrote:This solution does work but for a better understanding for myself why does this fix the issue and what causes this issue?
Apparently some of the saved session files were damaged somehow, possibly
tomcat crached while writing them, possibly hardware problems. Since session files are not critical resources, the best solution was just to get rid of them.
Note that when I say "not critical resources", I mean that if you delete them while Tomcat isn't running, the user session will have been terminated when Tomcat restarts, so the user will effectively have been logged off and lost work in progress. They're DEFINITELY critical while Tomcat is running!
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.