This problem is noticed in Version 2.50+160829 and also Version 2.56.1+161118 in a development site I just upgraded today. It doesn't matter what template is in use. Even wiping the templates and using those from the distribution (so I am using template 'default') sees the same behaviour. The best we get is a pop up dialog with "Save changes" on the bottom right but we are unable to do anything to select a file.

It is easy for us to reproduce. Create a new survey with a test question type of "File Upload". Preview the survey. There will be a button or a text link, depending on the template, for "Upload files". The link either does nothing in one template, or brings up a pop up window which does nothing in the other template.

Hi, seems to be really strange.
Here is what I see in Version Version 2.56.1+161118, template "default".
You see, I was able to select a file and it was uploaded.

So, I think you have to provide more details.

Best regards
Joffm

We are running Redhat Linux 6. php 5.5.38 from webtatic repository. There are no apache errors. Multiple users are experiencing the problem so it isn't a browser issue. The uploads and tmp under limesurvey are owned by the apache user and writable by owner.

I've set debug to 1, erased browser history and there is no change in the screen, no errors in screen nor log file.

This problem is now resolved. There was no error from Firefox and Chrome, but IE did show an error about iframe. Developer mode in chrome also revealed some hints.

We had some over-zealous settings in the SSL config:

Header always set Strict-Transport-Security "max-age=63072000; includeSubdomains; preload"
Header always set X-Frame-Options DENY
Header always set X-Content-Type-Options nosniff

When these were removed from the SSL virtual host configuration in apache, the file selector worked again as designed, in either version of Lime Survey.