Call to protected TGM_Plugin_Activation::__construct() from invalid context'. Help!
This issue was fixed in TGMPA v2.5.2. There are at least two copies of TGMPA active in your WP install and both of them are out-of-date. Please contact the theme/plugin authors of the theme/plugins using the old version of TGMPA and urge them to upgrade the TGMPA version they include.