Ok just realized you have an older prosper, which didn't put the DEFINE consts in quotes. This is prob the issue. Your php.ini file or version likely was updated/changed, and now PHP isn't understanding this old school use of the define constant.
In english, you can try changing the first few lines to this:
DEFINE('TRACKING202_API_URL', 'https://api.tracking202.com');
DEFINE('TRACKING202_RSS_URL', 'http://rss.tracking202.com');
But you may get this issue further down the line if they did this elsewhere.