Firefox 46 were out in 2016. So I highly doubt that LimeSurvey is not working on Firefox 46.
I'd rather bet on a server configuration problem. Why this server configuration problem only affect Firefox version prior to 46? Probably because this is not the problem, but rather a specific configuration of Firefox security settings that's OP haven't notice.

See:
developer.mozilla.org/en-US/docs/Mozilla...tworking_preferences
kb.mozillazine.org/Links_to_local_pages_don't_work

olle wrote: Do you have infinite of money? Because that's what we need if you want to support ALL browsers in the wild.

I was scared to get such an answer. It's those answers that makes it sometimes hard to believe in the project. No one talks about "ALL" browsers. But the Firefox mentioned was out in April 2016 and this is a little bit older than 1,5 years (besides it being a Beta version, which I think we do not have to support).

Luckily you relativated it the following:

We should rather have a more manageable goal, like supporting 98-99% of all the browsers in the wild.

I would actually not even go that far. 95% should be pretty fine. I know that browser support isn't an easy thing and can be sometimes really, really annoying because some browser developers don't follow standards, invent new things, display things totally different than the rest, etc.

Unfortunately when it comes to a survey system we need to be quite "conservative" when it comes to browsers. As I said, for the backend it is relatively easy and the potential user might have to update (still hard enough in some company environments). But there is no way to control what browsers respondents use (despite for internal surveys in a company). In market research representativity is often very important and if you tell a client: Sorry, our survey system only supports the latest browsers they will think you are crazy. So if LS wants paying users, there needs to be a reasonable support for older browsers as well. I am saying reasonable because it goes without saying, that it is not feasible to support ALL browsers (which was never requested in the thread anyway).

But as I said, with your second post and with LouisGac's comment your first comment stands in a different light and was probably not meant as it was written.

And the browser thing isn't getting easier. While I understand that supporting Microsoft browsers has gotten easier to a certain extent, we are facing other challenges like mobile browsing, etc.

I also had a quick look at some browser statistics (which I hadn't done for a while) and was surprised that there is a new player in the top 5! UC Browser.

gs.statcounter.com/

While all these statistics have to be taken with a grain of salt, I think they can give us at least a good idea what we need to support.

The 6 browsers at the top only reach 90,74% of the population world wide (Worldwide because I think Limesurvey needs to think in those terms). But I think if these 6 browsers run the LS questionnaires fine we should be OK.

But there are huge differences in usage between countries.

I.e. Brazil has a above average share of computer users, while India has most of it's access via mobile.

I know it is not an easy task, but I think the questionnaires must run for any of those browsers and any of it versions of the last 2-4 years. Luckily browsers like Chrome and Firefox update automatically now, which means most of the users of those browsers should be fairly up to date.

But seeing how many systems are still with Windows XP (and accessing the INTERNET!!!!!) gives you an idea how some people care about updating.

But then again, there are huge differences in between countries. In Brazil XP is below 2%, for the African continent it is almost 7%

So yes, we can't guarantee that every single browser that is out there can be supported. But if one more or less "recent" Firefox Version doesn't work, there is a good chance that others don't either. If this is just a server configuration problem as Louis is expecting, well then fine. If it is only in this specific beta version: also fine. We definitely can't support betas. But we shouldn't brush browser compatibility issues off easily, even if they are a pain.

UC browser seems based on webkit, so it should work. AFAIK, there might be many browsers out there but only a handful of browser engine.