I forgot to write that I commented the following lines (in file /srv/www/limesurvey/scripts/admin/listresponse.js) in order to help.
(Thank you Denis!)

    beforeRequest: function(){
        /* activate tooltip on header */
        for (i = 0; i < colModels.length; i++) {
            var col=i+1;
            $("tr.ui-jqgrid-labels th:eq("+col+") .questiontext").attr('title',colModels[i]['title']);
        }
        $(".ui-jqgrid-labels").tooltip();
    },

While browsing the responses, it could be a good idea to display only 2 columns (Files names and File count) instead of 1 column per files.

The issue is too in HTML produced : 5000 columns for a page .... : break.

gantier have then issue in real with ~40 upload questions with 99 for max number of files.

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=19410

Hello, I pacthed my application/controllers/admin/responses.php with thoses modifications but it seems nothing changed.

There are still 4 columns per file-upload question : so if maxfile = 50, there are 200 columns displayed.

As I am not sure to understand how you wanted to fix the bug I prefer to tell you :)

Version 2.50 Build 160613 released