ok some news about my problem,

I upgraded the RFX from a computer with the rfxflash software, now I can upgrade from domoticz but only from a windows computer, not a ubuntu one.

Yes I can

So there is nothing in the log file, but i see a 404 error in the debug console of the web browser for what I think to be the firmware upgrader

I'll test it tonight, I can't do it at work

I tried to upgrade with firefox and chrome, same result, I also deleted the web cache.

Good job for the reactivity, gizmocuz!!
Just tried in the #4192 and still doesn't work, there is something wrong with me....

Hello,
In the latest beta (#4159 as now) and some before (I remember I tried in the #4031) I try to update my RRFX433E firmware, but As soon as I push the upgrade button I return to the dashboard.

Is it broken ? do I have to use the windows method ?