When I generate the statistics in expert mode PDF including graphics it gives me the following error:



Internal Server Error
Cannot use string offset as an array



Version of Php 7.1
Last version Limesurvey 3.4.2


I have attached the .lsa file of the survey.

You are posting real data in a public forum? The LSA contains responses of people.

I cannot reproduce the issue under 3.4.2 with PHP 5.6
You should report the issue via bugtracker. Might be a issue with PHP 7.1.

No, the data of the survey is fake data, posted by me.

I'm testing in a development environment

Thanks.

Ok, fine. Then we don't need to remove it. I recommend using LS under POSIX (e.g.Linux).
But as you opened a ticket, you might give LS 3.4.3 a last try under Windows.
bugs.limesurvey.org/view.php?id=13423