Which PHP version are you using?

what is the proper code to fix the issue and replace my pseudo=Patch" ?

[Wed Feb 26 06:33:20.658540 2020] [php7:notice] [pid 25366] [client 5.173.171.126:45316] Error: Length must be greater than 0 in /var/www/html/libraries/ossn.lib.system.php:764

Yes - it stopped the install with a reddish background notice to mail the admin of portal. now all worlks now but i am affraid due to my lack of understanding of ossn and my pseudo"-patch" somethin gwill go wrong in the future

From what I see in your log this is only a PHP notice.
So did it really stop continuing your installation at this point?

please dont laugh but I just wanted to make it go :

$size    = openssl_cipher_iv_length('bf-ecb');
$mcgetvi = 64; //openssl_random_pseudo_bytes($size); <<-- this returns zero which in turn causes an error
//note mcrypt and now this acting mcrpyt adds the spaces to make 16 bytes if its less then 16 bytes
//you can use trim() to get orignal data without spaces
return openssl_decrypt($string, "bf-ecb", $key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $mcgetvi);

You did exactly what?

I hardcoded it to 64 byte size and I KNOW its wrong -- :/// is there a decent fix ???

I can see that the website is working , seems the old error.