Occasionally respondents contact me to let me know that they received a session time-out message. I go in and find their record and sometimes they have only been in the survey for 20 minutes, when other people have been in there for 4 hours+ without any issues.

Ages ago I revised the Limesurvey timeout setting to be something insane like 10 hours, and checked with the hosting provider that their server doesn't time-out.

Does anyone know what else I can do to try to stop random sessions from timing out on people?

Hi,

There can be different reason of timeout but you can try github.com/SondagesPro/limesurvey-plugin-heartbeat .

tixeon wrote: I go in and find their record and sometimes they have only been in the survey for 20 minutes, when other people have been in there for 4 hours+ without any issues.

There is no hard time limit with the session. The session timelimit is counted against inactivity.
When you're using a survey with group by group and the session is e.g. 1440sec (default value for PHPsessions), you need a click on the "next button" every 24 min (you might find longer timespans, cause a session is only marked for deletion after the timelimit. The deletion itself can happen with a delay.

You might check your relevant php.ini settings for sessions.
php.net/manual/en/session.configuration.php