Warning: Declaration of ... Debug errors

Good day!

OJS 3.1.2.1

As you see (below) site has 6 (six) problems and i want to solve it.
I`m will be very apriciate if you help me.
Because i haven’t an idea how to fix it
Thx to all

Warning: Declaration of HypothesisPlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/hypothesis/HypothesisPlugin.inc.php on line 67
Warning: Declaration of CoinsPlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/coins/CoinsPlugin.inc.php on line 133
Warning: Declaration of AddThisPlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/addThis/AddThisPlugin.inc.php on line 168
Warning: Declaration of JatsTemplatePlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/jatsTemplate/JatsTemplatePlugin.inc.php on line 261
Warning: Declaration of CustomBlockPlugin::getBlockContext() should be compatible with BlockPlugin::getBlockContext($contextId = NULL) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 134
Warning: Declaration of DRIVERDAO::setOAI(&$oai) should be compatible with PKPOAIDAO::setOAI($oai) in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/plugins/generic/driver/DRIVERDAO.inc.php on line 19 Notice: Only variables should be assigned by reference in /var/www/dpnlab/data/www/jrnls.ivet.edu.ua/pages/index/IndexHandler.inc.php on line 68