I have this error when i try to use gnusocial with PHP 7.0.12 on Debian Jessie :

PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpsecl 2016/11/09 12:28:47 [error] 13790#13790: *1098 FastCGI sent in stderr: "nusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565 PHP message: PHP Notice: Undefined offset: 20 in /var/www/gnusocial/plugins/OStatus/extlib/phpseclib/Math/BigInteger.php on line 3565

It happens when you try to post with AndStatus.

It's seems to create an infinite loop.

PHP Version : PHP 7.0.12-1~dotdeb+8.1 (cli) ( NTS ) Copyright (c) 1997-2016 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies with Zend OPcache v7.0.12-1~dotdeb+8.1, Copyright (c) 1999-2016, by Zend Technologies

Regards