Indexhibit Support

Hello,

I can't upload any new exhibit.
1st I got this message : "filesource class not found".
But now I only have a firefox error message saying (in french) :
"The connection has been reset
The connection to the server has been reset while the page is loading.
The site may be temporarily unavailable or overloaded. Try again later;
If you can not navigate on any site, check the network connection of your computer; (>>>> no network problem)
If your computer or network is protected by a firewall or proxy, make sure Firefox is allowed to access the Web." (>>> no firewall, nor proxy, only adblock)

I'm using indexhibit 2.1 with mac OS10.9.5 + firefox63.0.3 + safari 9.1.3
mywebsite : cedrickeymenier.com

I have checked forum, but can't find solution, any help warmly welcome!
thanks
cédrick

... Only to say that I finally only have this error message
"filesource class not found"

NOT "the connection has been reset..."

thx

Sorry, I notice (again) I said something wrong :
my version of indexhibit is Indexhibit™ v2.0.1 (not 2.1)

I asked my webhost to update to PHP7 as advised by Vaska on a thread, but it makes my website disappear. So they switched back to PHP5.6 (saying it's the max PHP version for this indexhibit version 2.0.1

BTW I guess I should update Indexhibit to version 2.5
Could it be the reason of this "filesource class not found"?

(Sorry i'm literally lost in pixeland, and I got no map/knowledge. Unfortunately, in this situation, Yoko Ono's "Draw a map and get lost" doesn't really help.)