ArrowChat

Hi,
I am doing a new installation of my version of arrowchat 2.0.2.
at the final step of the installation, when this url is loading :
arrowchat/install/index.php?mode=final

20s later i get a systematic Internal Error 500.

I saw many posts like this one, but arrowchat support always conclude by "give me your credential and we'll help".
Can you please provide the technical answers as well ? That would help

Thank you in advance

Done by playing on the execution_timeout in php.ini