I don't get why so many participant's surveys are marked as incomplete, when it's obvious that they have completed the survey. In particular, I notice this with token surveys. I have 58 incomplete and 50 complete and I always have to include large numbers of the incomplete surveys (unless they are blank) as this survey is a registration form for students. I am running Version 2.50+ Build 160718 on OS X server but really, this issue has been around for as long as I have used LS. Just wondering if everyone else sees the same issue. Thanks.

What means "When it's obvious that they have completed the survey"? Have they reached the last page? Limesurvey only registers them as complete when the survey is correctly submitted. If this step is missing, it is not counting the respondent as complete. So let's first clarify what "they have completed means".

Anyway, there are several possibilites:
1. a bug in Limesurvey
2. a problem with OSX server in general (I guess no one ever tests with an OS X server...)
3. a problem with this specific server and its settings
4. problem with this specific survey
5. A problem with your students...
etc.

Can you show a link for example? In general, with the information you are giving it is hard to give any support, because it could be anything.