[Ash.]

I'm unsure as to whether this is related to the crash, but as far as I'm aware the function adds its parameter with a preceding question mark, so already having a pre-existing URL parameter will cause some problems.

Try this:

pawn Code:

format(string, 300, "?mode=register&username=%s&email=%s&email_confirm=%s&new_password=%s&password_confirm=%s&pf_in_game_name=%s&qa_answer=n", PlayerName(playerid), inputtext, inputtext, PlayerInfo[playerid][Ppassword], PlayerInfo[playerid][Ppassword], PlayerName(playerid));
HTTP(playerid, HTTP_POST, "mawebsite.com/forum/ucp.php", string, "OnForumRegister");

Possible PHP Issue: In "ucp.php", if it checks for "$_GET['mode'] == register" through a $_GET variable, replace $_GET with $_REQUEST and it will still work as intended.