We pushed some new code to API, and we accidentally used syntax â€‹â€‹that is available only in PHP 5.4 and up.
Your site has very old PHP 5.3 which caused a problem. We replaced that code with compatible, but we still recommend you to update your server.
PHP 5.3: Released: 30 June 2009 (5 years ago)â€‹â€‹, Reached “End of Life” 14 Aug 2014 (1 year, 6 months ago)
Current PHP version is 7.0â€‹â€‹.4