Merge remote-tracking branch 'origin/MAGETWO-58370' into public-prs2

Author: eug123

lib/internal/Magento/Framework/View/Layout/Generator/Block.php

@@ -261,7 +261,10 @@ protected function getBlockInstance($block, array $arguments = [])
         }
         if (!$block instanceof \Magento\Framework\View\Element\AbstractBlock) {
             throw new \Magento\Framework\Exception\LocalizedException(
-                new \Magento\Framework\Phrase('Invalid block type: %1', [$block]),
+                new \Magento\Framework\Phrase(
+                    'Invalid block type: %1',
+                    [is_object($block) ? get_class($block) : (string) $block]
+                ),
                 $e
             );
         }